Imaging lens and imaging apparatus

ABSTRACT

An imaging lens substantially consists of six lenses of a negative first lens, a negative second lens, a positive third lens, a positive fourth lens, a negative fifth lens and a positive sixth lens in this order from an object side. An object-side surface of the second lens has a shape having negative refractive power at a center, and including a part having positive refractive power in an area between the center and an effective diameter edge, and having negative refractive power at the effective diameter edge (concave shape facing the object side), and the refractive power at the effective diameter edge being weaker than the refractive power at the center. Further, an object-side surface of the third lens is convex toward the object side. Further, a predetermined conditional formula about a combined focal length of the first lens, the second lens and the third lens is satisfied.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an imaging lens and an imaging apparatus. In particular, the present invention relates to an imaging lens appropriate for use in an in-vehicle camera, a camera for a mobile terminal, a surveillance camera, or the like using an imaging device, such as a CCD (Charge Coupled Device) and a CMOS (Complementary Metal Oxide Semiconductor). Further, the present invention relates to an imaging apparatus including the imaging lens.

2. Description of the Related Art

In recent years, the size of an imaging device, such as a CCD and a CMOS, became very small, and the resolution of the imaging device became very high. Consequently, the size of the body of imaging equipment including such an imaging device became small. Therefore, reduction in the size of an imaging lens to be mounted on the imaging equipment is also needed in addition to excellent optical performance of the imaging lens. Meanwhile, lenses mounted on an in-vehicle camera, a surveillance camera and the like need to be structurable in small size and at low cost, and to achieve a wide angle of view and high performance.

Japanese Unexamined Patent Publication No. 2006-349920 (Patent Document 1), Japanese Unexamined Patent Publication No. 2010-160479 (Patent Document 2), Japanese Unexamined Patent Publication No. 2010-243709 (Patent Document 3), Specification of U.S. Pat. No. 7,023,628 (Patent Document 4), Japanese Unexamined Patent Publication No. 2005-221920 (Patent Document 5), Specification of U.S. Pat. No. 7,933,078 (Patent Document 6), Specification of U.S. Pat. No. 7,768,719 (Patent Document 7), Japanese Unexamined Patent Publication No. 2008-076716 (Patent Document 8), Japanese Unexamined Patent Publication No. 2009-092797 (Patent Document 9), Japanese Unexamined Patent Publication No. 2009-092798 (Patent Document 10), Japanese Unexamined Patent Publication No. 2010-009028 (Patent Document 11) and Japanese Unexamined Patent Publication No. 2008-134494 (Patent Document 12) disclose lens systems consisting of six lenses. The lens system is usable in a camera on which a small-size CCD is mounted, and uses a plastic aspheric lens.

SUMMARY OF THE INVENTION

Meanwhile, requirements for an imaging lens to be mounted on an in-vehicle camera, a surveillance camera or the like have become tougher every year. Therefore, further reduction in the size and the cost of the imaging lens, a wider angle of view, and higher performance are needed.

However, in the lens system disclosed in Patent Document 1, a half angle of view is 40° or less. Therefore, the angle of view of the lens system is not sufficiently wide. Further, the lens systems disclosed in Patent Documents 4, 5 and 6 use cemented lenses. Therefore, the lens systems are advantageous to chromatic aberrations and sensitivity. However, special cementing material and processing is required depending on usage conditions of the lens systems, and that increases the cost. Further, the lens system disclosed in Patent Document 7 is an anamorphic lens. Therefore, it is impossible to produce the lens system at low cost.

In view of the foregoing circumstances, it is an object of the present invention to provide an imaging lens that can achieve small size, low cost, a wide angle of view, and high performance and an imaging apparatus including the imaging lens.

An imaging lens according to a first aspect of the present invention is an imaging lens substantially consisting of six lenses of a negative first lens, a negative second lens, a positive third lens, a positive fourth lens, a negative fifth lens and a positive sixth lens in this order from an object side,

wherein an object-side surface of the second lens has a shape having negative refractive power at a center, and including a part having positive refractive power in an area between the center and an effective diameter edge, and having negative refractive power at the effective diameter edge, and the refractive power at the effective diameter edge being weaker than the refractive power at the center, and

wherein an object-side surface of the third lens is convex toward the object side.

The expression “having negative refractive power at the effective diameter edge” means that the shape at the effective diameter edge is a concave shape facing the object side.

The expression “a shape, the refractive power at the effective diameter edge being weaker than the refractive power at the center” means “a shape in which the refractive power at the effective diameter edge is weaker than the refractive power at the center” regardless of whether the refractive power is positive refractive power or negative refractive power.

An imaging lens according to a second aspect of the present invention is an imaging lens substantially consisting of six lenses of a negative first lens, a negative second lens, a positive third lens, a positive fourth lens, a negative fifth lens and a positive sixth lens in this order from an object side,

wherein the material of the first lens, the fourth lens and the fifth lens is glass, and the material of the second lens, the third lens and the sixth lens is plastic.

An imaging lens according to a third aspect of the present invention is an imaging lens substantially consisting of six lenses of a negative first lens, a negative second lens, a positive third lens, a positive fourth lens, a negative fifth lens and a positive sixth lens in this order from an object side,

wherein the following conditional formula (21) is satisfied: 2.5<ER1/f<7.5  (21), where

ER1: an effective radius of an object-side surface of the first lens, and

f: a focal length of an entire system.

The expression “substantially consisting of six lenses” means that lenses substantially without any refractive power, optical elements other than lenses, such as a stop and a cover glass, mechanical parts, such as a lens flange, a lens barrel, an imaging device, and a hand shake blur correction mechanism, and the like may be included in addition to the six lenses.

The imaging lenses according to the first through third aspects of the present invention substantially consist of six lenses. Therefore, it is possible to obtain excellent optical performance. Further, since the number of lenses is suppressed, it is possible to reduce the size of the imaging lens, and to suppress the cost of the imaging lens.

In the present invention, the surface shape of a lens, such as a convex surface, a concave surface, a flat surface, biconcave, meniscus, biconvex, plano-convex and plano-concave, and the sign of the refractive power of a lens, such as a positive lens and a negative lens, are considered in a paraxial region when a lens includes an aspherical surface, unless otherwise mentioned. Further, in the present invention, the sign of a curvature radius is positive when a surface shape is convex toward an object side, and negative when a surface shape is convex toward an image side.

In the imaging lenses according to the first and second aspects of the present invention, it is desirable that the following conditional formulas (11) through (20) and (21-1) are satisfied. In the imaging lens according to the third aspect of the present invention, it is desirable that the following conditional formulas (11) through (20) are satisfied. As a desirable mode, an imaging lens may include a structure of one of the following conditional formulas (11) through (20) and (21-1), or a structure of arbitrary two or more of them in combination: 9<L/f<16  (11); 1<Bf/f<3  (12); vd3+vd5<50.00  (13); 0.2≦(R3+R4)/(R3−R4)≦1.0  (14); −10≦(R5+R6)/(R5−R6)≦−1  (15); 1.1≦(R1+R2)/(R1−R2)≦3.0  (16); −5<f123/f<−1.0  (17); 2<f3/f<12  (18): 0.01<D9/f<0.5  (19): 1.0<f4/f<4.0  (20); and 2.5<ER1/f<8  (21-1), where

L: a length from an object-side surface of a first lens to an image plane on an optical axis (a back focus portion is a distance in air),

f: a focal length of an entire system,

Bf: a length from an image-side surface of a most image-side lens to an image plane on an optical axis (a distance in air),

vd3: an Abbe number of the material of a third lens for d-line,

vd5: an Abbe number of the material of a fifth lens for d-line,

R1: a curvature radius of an object-side surface of a first lens,

R2: a curvature radius of an image-side surface of a first lens,

R3: a curvature radius of an object-side surface of a second lens,

R4: a curvature radius of an image-side surface of a second lens,

R5: a curvature radius of an object-side surface of a third lens,

R6: a curvature radius of an image-side surface of a third lens,

f123: a combined focal length of a first lens, a second lens and a third lens,

f3: a focal length of a third lens,

f4: a focal length of a fourth lens,

D9: an air space between a fourth lens and a fifth lens on an optical axis, and

ER1: an effective radius of an object-side surface of a first lens.

Regarding length L from an object-side surface of a first lens to an image plane on an optical axis and length Bf from an image-side surface of a most image-side lens to an image plane on an optical axis, a distance in air is used for the length from the most image-side lens to the image plane (When a cover glass or various filters are provided, a portion corresponding to such elements is converted into a distance in air, and the length is calculated by using the distance in air).

An imaging apparatus of the present invention includes at least one of the first through third imaging lenses of the present invention.

According to the imaging lens in the first aspect of the present invention, the arrangement of refractive power in the entire system, the shapes of the surfaces of the second lens and the third lens, and the like are appropriately set in the lens system including at least six lenses. Therefore, it is possible to achieve small size, low cost, and a wide angle of view. Further, it is possible to realize an imaging lens having high optical performance in which various aberrations are excellently corrected, and an excellent image is obtainable even in a peripheral portion of an image formation area.

According to the imaging lens in the second aspect of the present invention, the arrangement of refractive power in the entire system, the material of each lens and the like are appropriately set in the lens system including at least six lenses. Therefore, it is possible to achieve small size, low cost, and a wide angle of view. Further, it is possible to realize an imaging lens having high optical performance in which various aberrations are excellently corrected, and an excellent image is obtainable even in a peripheral portion of an image formation area.

According to the imaging lens in the third aspect of the present invention, the arrangement of refractive power in the entire system and the like are appropriately set, and conditional formula (21) is satisfied in the lens system including at least six lenses. Therefore, it is possible to achieve small size, low cost, and a wide angle of view. Further, it is possible to realize an imaging lens having high optical performance in which various aberrations are excellently corrected, and an excellent image is obtainable even in a peripheral portion of an image formation area.

The imaging apparatus of the present invention includes the imaging lens of the present invention. Therefore, the imaging apparatus is structurable in small size and at low cost. Further, the imaging apparatus can perform photography with a wide angle of view, and obtain an excellent image with high resolution.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating the structure of an imaging lens according to an embodiment of the present invention, and optical paths;

FIG. 2 is a diagram for explaining the surface shape of a second lens, and the like;

FIG. 3 is a cross section illustrating the lens structure of an imaging lens in Example 1 of the present invention;

FIG. 4 is a cross section illustrating the lens structure of an imaging lens in Example 2 of the present invention;

FIG. 5 is a cross section illustrating the lens structure of an imaging lens in Example 3 of the present invention;

FIG. 6 is a cross section illustrating the lens structure of an imaging lens in Example 4 of the present invention;

FIG. 7 is a cross section illustrating the lens structure of an imaging lens in Example 5 of the present invention;

FIG. 8 is a cross section illustrating the lens structure of an imaging lens in Example 6 of the present invention;

FIG. 9 is a cross section illustrating the lens structure of an imaging lens in Example 7 of the present invention;

FIG. 10 is a cross section illustrating the lens structure of an imaging lens in Example 8 of the present invention;

FIG. 11 is a cross section illustrating the lens structure of an imaging lens in Example 9 of the present invention;

FIG. 12 is a cross section illustrating the lens structure of an imaging lens in Example 10 of the present invention;

FIG. 13 is a cross section illustrating the lens structure of an imaging lens in Example 11 of the present invention;

FIG. 14 is a cross section illustrating the lens structure of an imaging lens in Example 12 of the present invention;

FIG. 15 is a cross section illustrating the lens structure of an imaging lens in Example 13 of the present invention;

FIG. 16 is a cross section illustrating the lens structure of an imaging lens in Example 14 of the present invention;

FIG. 17 is a cross section illustrating the lens structure of an imaging lens in Example 15 of the present invention;

FIG. 18 is a cross section illustrating the lens structure of an imaging lens in Example 16 of the present invention;

FIG. 19 is a cross section illustrating the lens structure of an imaging lens in Example 17 of the present invention;

FIG. 20 is a cross section illustrating the lens structure of an imaging lens in Example 18 of the present invention;

FIG. 21 is a cross section illustrating the lens structure of an imaging lens in Example 19 of the present invention;

FIG. 22, Sections A through D are aberration diagrams of the imaging lens in Example 1 of the present invention;

FIG. 23, Sections A through D are aberration diagrams of the imaging lens in Example 2 of the present invention;

FIG. 24, Sections A through D are aberration diagrams of the imaging lens in Example 3 of the present invention;

FIG. 25, Sections A through D are aberration diagrams of the imaging lens in Example 4 of the present invention;

FIG. 26, Sections A through D are aberration diagrams of the imaging lens in Example 5 of the present invention;

FIG. 27, Sections A through D are aberration diagrams of the imaging lens in Example 6 of the present invention;

FIG. 28, Sections A through D are aberration diagrams of the imaging lens in Example 7 of the present invention;

FIG. 29, Sections A through D are aberration diagrams of the imaging lens in Example 8 of the present invention;

FIG. 30, Sections A through D are aberration diagrams of the imaging lens in Example 9 of the present invention;

FIG. 31, Sections A through D are aberration diagrams of the imaging lens in Example 10 of the present invention;

FIG. 32, Sections A through D are aberration diagrams of the imaging lens in Example 11 of the present invention;

FIG. 33, Sections A through D are aberration diagrams of the imaging lens in Example 12 of the present invention;

FIG. 34, Sections A through D are aberration diagrams of the imaging lens in Example 13 of the present invention;

FIG. 35, Sections A through D are aberration diagrams of the imaging lens in Example 14 of the present invention;

FIG. 36, Sections A through D are aberration diagrams of the imaging lens in Example 15 of the present invention;

FIG. 37, Sections A through D are aberration diagrams of the imaging lens in Example 16 of the present invention;

FIG. 38, Sections A through D are aberration diagrams of the imaging lens in Example 17 of the present invention;

FIG. 39, Sections A through D are aberration diagrams of the imaging lens in Example 18 of the present invention;

FIG. 40, Sections A through D are aberration diagrams of the imaging lens in Example 19 of the present invention; and

FIG. 41 is a diagram for explaining the arrangement of imaging apparatuses for in-vehicle use according to an embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be described in detail with reference to drawings.

[Embodiments of Imaging Lens]

First, imaging lenses according to embodiments of the present invention will be described with reference to FIG. 1. FIG. 1 is a diagram illustrating the structure of an imaging lens 1 according to an embodiment of the present invention, and optical paths. The imaging lens 1 illustrated in FIG. 1 corresponds to an imaging lens in Example 1 of the present invention, which will be described later.

In FIG. 1, the left side is the object side and the right side is the image side, and axial rays 2 from an object point at infinity, off-axial rays 3, 4 at full angle of view 2ω and effective radius ER1 of an object-side surface of the first lens are also illustrated. In FIG. 1, application of the imaging lens 1 to an imaging apparatus is considered, and an imaging device 5 arranged at image plane Sim including image point Pim of the imaging lens 1 is also illustrated. The imaging device 5 converts an optical image formed by the imaging lens 1 into electrical signals. For example, a CCD image sensor, a CMOS image sensor, or the like may be used as the imaging device 5.

When the imaging lens 1 is applied to an imaging apparatus, it is desirable to set a cover glass, and a low-pass filter or an infrared ray cut filter, or the like based on the structure of a camera on which the lens is mounted. FIG. 1 illustrates an example in which parallel-flat-plate-shaped optical member PP, which is assumed to be such elements, is arranged between the most image-side lens and the imaging device 5 (image plane Sim).

First, the structure of the first embodiment of the present invention will be described. An imaging lens according to the first embodiment of the present invention includes negative first lens L1, negative second lens L2, positive third lens L3, positive fourth lens L4, negative fifth lens L5 and positive sixth lens L6 in this order from the object side. In the example illustrated in FIG. 1, aperture stop St is arranged between third lens L3 and fourth lens L4. In FIG. 1, aperture stop St does not represent the shape nor the size of aperture stop St, but the position of aperture stop St on optical axis Z. Since aperture stop St is arranged between third lens L3 and fourth lens L4, it is possible to reduce the size of the entire system. When aperture stop St is located close to the object side, it is possible to easily reduce the outer diameter of first lens L1. However, if aperture stop St is too close to the object side, it becomes difficult to separate axial rays and off-axial rays from each other at first lens L1 and second lens L2, and to correct curvature of field. When aperture stop St is arranged between third lens L3 and fourth lens L4, it is possible to easily correct curvature of field while reducing the lens diameter.

This imaging lens consists of at least six lenses, which are a small number of lenses. Therefore, it is possible to reduce the cost and the total length of the imaging lens in the optical axis direction. Further, since both of first lens L1 and second lens L2, which are two lenses arranged on the object side, are negative lenses, it is possible to easily widen the angle of view of the entire lens system. Further, since two negative lenses are arranged on the most object side, negative refractive power can be shared by the two lenses, and it is possible to stepwise bend rays entering at a wide angle of view. Therefore, it is possible to effectively correct distortion. Further, there are also three positive lenses of third lens L3, fourth lens L4 and sixth lens L6. Therefore, these three lenses can share convergence action for forming an image on an image plane and correction of various aberrations to be performed by a positive lens or lenses. Hence, it is possible to effectively perform correction.

When third lens L3 is a positive lens, it is possible to excellently correct curvature of field. When fourth lens L4 is a positive lens and fifth lens L5 is a negative lens, it is possible to excellently correct a longitudinal chromatic aberration and a lateral chromatic aberration. When sixth lens L6 is a positive lens, it is possible to reduce an angle at which peripheral rays enter an image formation surface of the imaging lens. Therefore, it is possible to suppress shading. When fourth lens L4 is a positive lens, and fifth lens L5 is a negative lens, and sixth lens L6 is a positive lens, it is possible to excellently correct a spherical aberration and curvature of field. When negative refractive power, negative refractive power, positive refractive power, positive refractive power, negative refractive power and positive refractive power are arranged in this order from the object side, it is possible to obtain a lens system in small size and with a wide angle of view and excellent resolution performance even if the lens system has a small F-number.

Further, in the imaging lens according to the first embodiment, an object-side surface of second lens L2 has a shape having negative refractive power at a center, and including a part having positive refractive power in an area between the center and an effective diameter edge, and having negative refractive power at the effective diameter edge (a concave shape facing the object side), and the refractive power at the effective diameter edge is weaker than the refractive power at the center. When the object-side surface of second lens L2 has such a shape, it is possible to reduce the size of the lens system, and to widen an angle of view. At the same time, it is possible to excellently correct curvature of field and distortion. The shape of the object-side surface of second lens L2 will be described later in detail.

Further, in the imaging lens according to the first embodiment of the present invention, an object-side surface of third lens L3 is convex toward the object side. When the object-side surface of third lens L3 has such a shape, it is possible to easily reduce the size of the lens system in the direction of the system. Further, it is possible to excellently correct curvature of field and a coma aberration.

Next, the structure of a second embodiment of the present invention will be described. An imaging lens according to the second embodiment of the present invention includes negative first lens L1, negative second lens L2, positive third lens L3, positive fourth lens L4, negative fifth lens L5 and positive sixth lens L6 in this order from the object side.

This imaging lens consists of at least six lenses, which are a small number of lenses. Therefore, it is possible to reduce the cost and the total length of the imaging lens in the optical axis direction. Further, since both of first lens L1 and second lens L2, which are two lenses arranged on the object side, are negative lenses, it is possible to easily widen the angle of view of the entire lens system. Further, since two negative lenses are arranged on the most object side, negative refractive power can be shared by the two lenses, and it is possible to stepwise bend rays entering at a wide angle of view. Therefore, it is possible to effectively correct distortion. Further, there are also three positive lenses of third lens L3, fourth lens L4 and sixth lens L6. Therefore, these three lenses can share convergence action for forming an image on the image plane and correction of various aberrations to be performed by a positive lens or lenses. Hence, it is possible to effectively perform correction.

When third lens L3 is a positive lens, it is possible to excellently correct curvature of field. When fourth lens L4 is a positive lens and fifth lens L5 is a negative lens, it is possible to excellently correct a longitudinal chromatic aberration and a lateral chromatic aberration. When sixth lens L6 is a positive lens, it is possible to reduce an angle at which peripheral rays enter an image formation surface of the imaging lens. Therefore, it is possible to suppress shading. When fourth lens L4 is a positive lens, and fifth lens L5 is a negative lens, and sixth lens L6 is a positive lens, it is possible to excellently correct a spherical aberration and curvature of field. When negative refractive power, negative refractive power, positive refractive power, positive refractive power, negative refractive power and positive refractive power are arranged in this order from the object side, it is possible to obtain a lens system in small size and with a wide angle of view and excellent resolution performance even if the lens system has a small F-number.

In the imaging lens according to the second embodiment, the material of first lens L1, fourth lens L4 and fifth lens L5 is glass, and the material of second lens L2, third lens L3 and sixth lens L6 is plastic.

When an imaging lens is used in tough environment conditions, for example, such as use in an in-vehicle camera or a surveillance camera, first lens L1, which is arranged on the most object-side, needs to use a material resistant to a deterioration of a surface by wind and rain and a change in temperature by direct sun light, and resistant to chemicals, such as oils and fats and detergent. In other words, the material needs to be highly water-resistant, weather-resistant, acid-resistant, chemical-resistant, and the like. Further, in some cases, the material needs to be hard and not easily breakable. When the material of first lens L1 is glass, it is possible to satisfy such needs.

When the material of fourth lens L4 is glass, it is possible to suppress a deterioration of performance caused by a change in temperature. When the material of fifth lens L5 is glass, it is possible to easily select a material with a small Abbe number. Therefore, it is possible to easily correct chromatic aberrations.

Further, when the material of second lens L2, third lens L3 and sixth lens L6 is plastic, it is possible to structure the lens system at low cost and with light weight. Further, when an aspherical surface is provided, it is possible to accurately produce the aspherical shape. Therefore, it is possible to produce a lens with excellent performance.

Next, the structure of a third embodiment of the present invention will be described. An imaging lens according to the third embodiment of the present invention includes negative first lens L1, negative second lens L2, positive third lens L3, positive fourth lens L4, negative fifth lens L5 and positive sixth lens L6 in this order from the object side.

This imaging lens consists of at least six lenses, which are a small number of lenses. Therefore, it is possible to reduce the cost and the total length of the imaging lens in the optical axis direction. Further, since both of first lens L1 and second lens L2, which are two lenses arranged on the object side, are negative lenses, it is possible to easily widen the angle of view of the entire lens system. Further, since two negative lenses are arranged on the most object side, negative refractive power can be shared by the two lenses, and it is possible to stepwise bend rays entering at a wide angle of view. Therefore, it is possible to effectively correct distortion. Further, there are also three positive lenses of third lens L3, fourth lens L4 and sixth lens L6. Therefore, these three lenses can share convergence action for forming an image on the image plane and correction of various aberrations to be performed by a positive lens or lenses. Hence, it is possible to effectively perform correction.

When third lens L3 is a positive lens, it is possible to excellently correct curvature of field. When fourth lens L4 is a positive lens and fifth lens L5 is a negative lens, it is possible to excellently correct a longitudinal chromatic aberration and a lateral chromatic aberration. When sixth lens L6 is a positive lens, it is possible to reduce an angle at which peripheral rays enter an image formation surface of the imaging lens. Therefore, it is possible to suppress shading. When fourth lens L4 is a positive lens, and fifth lens L5 is a negative lens, and sixth lens L6 is a positive lens, it is possible to excellently correct a spherical aberration and curvature of field. When negative refractive power, negative refractive power, positive refractive power, positive refractive power, negative refractive power and positive refractive power are arranged in this order from the object side, it is possible to obtain a lens system in small size and with a wide angle of view and excellent resolution performance even if the lens system has a small F-number.

Further, the imaging lens according to the third embodiment of the present invention satisfies the following conditional formula (21): 2.5<ER1/f<7.5  (21), where

ER1: an effective radius of an object-side surface of first lens L1, and

f: a focal length of an entire system.

Here, if a part of an in-vehicle camera exposed to the outside is large, the appearance of the vehicle is damaged. Therefore, a part of the in-vehicle camera exposed to the outside needs to be reduced. When the upper limit of conditional formula (21) is satisfied, it is possible to easily reduce the effective diameter of first lens L1, and to easily suppress the part exposed to the outside so that the part becomes small. When the lower limit of conditional formula (21) is satisfied, it is possible to easily prevent the effective diameter of the object-side surface of first lens L1 from becoming too small. Further, it is possible to easily separate an optical path of central rays and an optical path of off-axial rays from each other at a front-side concave lens in the lens system. Therefore, it is possible to easily correct distortion and curvature of field.

Here, the term “effective radius” means the radius of a circle composed of outermost points (points farthest from an optical axis) in the direction of the diameter when points of intersection of all rays contributing to image formation and a lens surface are considered. When a system is rotationally symmetric with respect to an optical axis, a figure composed of the outermost points is a circle. However, when a system is not rotationally symmetric, a figure composed of the outermost points is not a circle in some cases. In such a case, an equivalent circle may be considered, and the radius of the equivalent circle may be regarded as an effective radius.

The imaging lenses according to the first through third embodiments may include at least one of the structures of the other embodiments, or at least one of desirable structures of the other embodiments. For example, the imaging lens according to the first embodiment may include the structure of the second embodiment. The imaging lens in the second embodiment may include a desirable structure described as the structure of the first embodiment.

Next, structures to be desirably included in the imaging lenses according to the first through third embodiments will be given, and the action and effect of the structures will be described. As a desirable mode, an imaging lens may include one of the following structures, or arbitrary two or more of them in combination.

It is desirable that the following conditional formula (11) is satisfied: 9<L/f<16  (11), where

L: a length from an object-side surface of first lens L1 to an image plane on an optical axis (a back focus portion is a distance in air), and

f: a focal length of an entire system.

If the value exceeds the upper limit of conditional formula (11), it is possible to easily widen the angle of view, but the size of the lens system becomes large. If the value is lower than the lower limit of conditional formula (11), it is possible to reduce the size of the lens system, but it becomes difficult to achieve a wide angle of view.

It is desirable that the following conditional formula (12) is satisfied: 1<Bf/f<3  (12), where

Bf: a length from an image-side surface of a most image-side lens to an image plane on an optical axis (a distance in air), and

f: a focal length of an entire system.

When the upper limit of conditional formula (12) is satisfied, it is possible to easily reduce the size of the lens system. When the lower limit of conditional formula (12) is satisfied, it is possible to easily secure a back focus.

It is desirable that the following conditional formula (13) is satisfied: vd3+vd5<50.0  (13), where

vd3: an Abbe number of the material of third lens L3 for d-line, and

vd5: an Abbe number of the material of fifth lens L5 for d-line.

When the upper limit of conditional formula (13) is satisfied, it is possible to easily reduce the Abbe number of third lens L3 and fifth lens L5, and correction of a longitudinal chromatic aberration and a lateral chromatic aberration becomes easy.

It is desirable that the following conditional formula (14) is satisfied: 0.2≦(R3+R4)/(R3−R4)≦1.0  (14), where

R3: a curvature radius of an object-side surface of second lens L2, and

R4: a curvature radius of an image-side surface of second lens L2.

Since second lens L2 is a negative lens, when conditional formula (14) is satisfied, second lens L2 can become a biconcave lens the absolute value of the curvature radius of the object-side surface of which is greater than the absolute value of the curvature radius of its image-side surface. It becomes possible to easily increase the refractive power of second lens L2, and to easily widen the angle of view. Further, correction of curvature of field and distortion becomes easy. Since second lens L2 is a negative lens, if the value exceeds the upper limit of conditional formula (14), second lens L2 becomes a meniscus lens with a convex surface facing the object side. When the upper limit of conditional formula (14) is satisfied, second lens L2 can become a biconcave lens, and correction of curvature of field and distortion becomes easy. When the lower limit of conditional formula (14) is satisfied, it is possible to prevent the absolute value of the curvature radius of the object-side surface of second lens L2 and the absolute value of the curvature radius of the image-side surface of second lens L2 from becoming close to each other. Therefore, it is possible to easily prevent the absolute value of the curvature radius of the object-side surface of second lens L2 from becoming too small, and correction of curvature of field becomes easy.

It is desirable that the following conditional formula (15) is satisfied: −10≦(R5+R6)/(R5−R6)≦−1  (15), where

R5: a curvature radius of an object-side surface of third lens L3, and

R6: a curvature radius of an image-side surface of third lens L3.

When the upper limit of conditional formula (15) is satisfied, the shape of third lens L3 can become a positive meniscus shape with a convex surface facing the object side, and correction of curvature of field becomes easy. When the lower limit of conditional formula (15) is satisfied, it is possible to prevent the curvature radius of the object-side surface of third lens L3 and the curvature radius of the image-side surface of third lens L3 from becoming close to each other, and to prevent the refractive power of third lens L3 from becoming too weak. Further, correction of curvature of field and a lateral chromatic aberration becomes easy.

It is desirable that the following conditional formula (16) is satisfied: 1.1≦(R1+R2)/(R1−R2)≦3.0  (16), where

R1: a curvature radius of an object-side surface of first lens L1, and

R2: a curvature radius of an image-side surface of first lens L1.

When the upper limit of conditional formula (16) is satisfied, it is possible to prevent the curvature radius of the object-side surface of first lens L1 and the curvature radius of the image-side surface of first lens L1 from becoming too close to each other. Further, it is possible to easily increase the refractive power of first lens L1. Therefore, it becomes possible to easily widen the angle of view. When the lower limit of conditional formula (16) is satisfied, it is possible to easily reduce the curvature radius of the object-side surface of first lens L1, and correction of distortion becomes easy.

It is desirable that the following conditional formula (17) is satisfied: −5<f123/f<−1.0  (17), where

f123: a combined focal length of first lens L1, second lens L2 and third lens L3, and

f: a focal length of an entire system.

If the value exceeds the upper limit of conditional formula (17), the negative refractive power of first lens L1 and second lens L2 becomes strong, and it is possible to easily widen the angle of view. However, correction of curvature of field becomes difficult, or the refractive power of third lens L3 becomes weak. Therefore, correction of a lateral chromatic aberration becomes difficult. If the value is lower than the lower limit of conditional formula (17), the negative refractive power of first lens L1 and second lens L2 becomes weak, and it becomes difficult to widen the angle of view, or the size of the lens system becomes large.

It is desirable that the following conditional formula (18) is satisfied: 2<f3/f<12  (18), where

f3: a focal length of third lens L3, and

f: a focal length of an entire system.

When the upper limit of conditional formula (18) is satisfied, it is possible to prevent the refractive power of third lens L3 from becoming too weak, and correction of curvature of field and a lateral chromatic aberration becomes easy. When the lower limit of conditional formula (18) is satisfied, it is possible to easily increase the back focus.

It is desirable that the following conditional formula (19) is satisfied: 0.01<D9/f<0.5  (19), where

f: a focal length of an entire system, and

D9: an air space between fourth lens L4 and fifth lens L5 on an optical axis.

When the upper limit of conditional formula (19) is satisfied, it is possible to easily reduce the distance between fifth lens L4 and fifth lens L5, and correction of chromatic aberrations becomes easy. Further, it is possible to easily reduce the size of the lens system. When the lower limit of conditional formula (19) is satisfied, it is possible to provide an air space between fourth lens L4 and fifth lens L5. Therefore, fourth lens L4 and fifth lens L5 do not constitute a cemented lens. When the lens system is used, for example, in an in-vehicle camera, where environment-resistance is required, a cemented lens causes an increase in cost because it is necessary to use a special adhesive for increasing the environment-resistance or to perform processing for increasing the environment-resistance, depending on required conditions. Therefore, it is desirable that fourth lens L4 and fifth lens L5 are not a cemented lens.

It is desirable that the following conditional formula (20) is satisfied: 1.0<f4/f<4.0  (20), where

f4: a focal length of fourth lens L4, and

f: a focal length of an entire system.

When the upper limit of conditional formula (20) is satisfied, it is possible to easily increase the refractive power of fourth lens L4, and correction of chromatic aberrations becomes easy. When the lower limit of conditional formula (20) is satisfied, it is possible to easily secure a back focus.

In the imaging lenses especially in the first and second embodiments of the present invention, it is desirable that the following conditional formula (21-1) is satisfied: 2.5<ER1/f<8  (21-1), where

ER1: an effective radius of an object-side surface of first lens L1, and

f: a focal length of an entire system.

Here, if a part of an in-vehicle camera exposed to the outside is large, the appearance of the vehicle is damaged. Therefore, the part of the in-vehicle camera exposed to the outside needs to be reduced. When the upper limit of conditional formula (21-1) is satisfied, it is possible to easily reduce the effective diameter of first lens L1, and to easily suppress the part exposed to the outside so that the part becomes small. When the lower limit of conditional formula (21-1) is satisfied, it is possible to easily prevent the effective diameter of the object-side surface of first lens L1 from becoming too small. Further, it is possible to easily separate an optical path of central rays and an optical path of off-axial rays from each other at a front-side concave lens in the lens system. Therefore, it is possible to easily correct distortion and curvature of field.

Regarding each of the aforementioned conditional formulas, it is desirable to satisfy a conditional formula in which an upper limit is further added, or a conditional formula in which a lower limit or an upper limit is modified, as will be described below. As a desirable mode, a conditional formula using a modified lower limit and a modified upper limit, as will be described next, in combination may be satisfied. Desirable modification examples of conditional formulas will be described next, as examples. However, the modification examples of the conditional formulas are not limited to those represented by the following expressions. The described modification values may be used in combination.

It is desirable that the upper limit of conditional formula (11) is 15.8. When the upper limit of conditional formula (11) is 15.8, it is possible to more easily reduce the size of the lens system. It is more desirable that the upper limit of conditional formula (11) is 15.3, and it is even more desirable that the upper limit of conditional formula (11) is 15.0.

It is desirable that the lower limit of conditional formula (11) is 11. When the lower limit of conditional formula (11) is 11, it is possible to more easily widen the angle of view. It is more desirable that the lower limit of conditional formula (11) is 12, and it is even more desirable that the lower limit of conditional formula (11) is 12.5.

Therefore, for example, it is desirable that the following conditional formula (11-1), (11-2) or (11-3) is satisfied: 11<L/f<15.8  (11-1); 12<L/f<15.3  (11-2); or 12.5<L/f<15.0  (11-3).

It is desirable that the upper limit of conditional formula (12) is 2.8. When the upper limit of conditional formula (12) is 2.8, it is possible to more easily reduce the size of the lens system. It is more desirable that the upper limit of conditional formula (12) is 2.5 to reduce the size, and it is even more desirable that the upper limit is 2.4. It is still more desirable that the upper limit is 2.3.

It is desirable that the lower limit of conditional formula (12) is 1.5. When the lower limit of conditional formula (12) is 1.5, it is possible to more easily secure a back focus. It is more desirable that the lower limit of conditional formula (12) is 1.6, and it is even more desirable that the lower limit of conditional formula (12) is 1.7.

Therefore, for example, it is desirable that the following conditional formula (12-1) or (12-2) is satisfied: 1.5<Bf/f<2.8  (12-1); or 1.7<Bf/f<2.3  (12-2).

It is desirable that the upper limit of conditional formula (13) is 49.5. When the upper limit of conditional formula (13) is 49.5, it is possible to more easily correct a longitudinal chromatic aberration and a lateral chromatic aberration. It is desirable that the upper limit of conditional formula (13) is 48.0 to correct chromatic aberrations, and it is more desirable that the upper limit is 45.0.

It is desirable to set a lower limit for conditional formula (13). In this case, it is desirable that the lower limit is 30.0. When the lower limit of conditional formula (13) is 30.0, it is possible to easily suppress the cost of the material of third lens L3 and fifth lens L5. Therefore, it is possible to easily suppress the cost of the whole lens. It is desirable that the lower limit of conditional formula (13) is 32.0 to suppress the cost of the material of third lens L3 and fifth lens L5. It is desirable that the lower limit of conditional formula (13) is 34.0 to further suppress the cost. It is more desirable that the lower limit is 38.0, and it is even more desirable that the lower limit is 40.0.

Therefore, for example, it is desirable that the following conditional formula (13-1), (13-2) or (13-3) is satisfied: 34.0<vd3+vd5<50.0  (13-1); 38.0<vd3+vd5<48.0  (13-2); or 40.0<vd3+vd5<45.0  (13-3).

It is desirable that the upper limit of conditional formula (14) is 0.9. When the upper limit of conditional formula (14) is 0.9, it is possible to easily reduce the absolute value of the curvature radius of the object-side surface of the second lens while the second lens is a biconcave lens. Therefore, it is possible to more easily widen the angle of view, and to more easily correct curvature of field and distortion. It is more desirable that the upper limit of conditional formula (14) is 0.85 to easily widen the angle of view, and to easily correct curvature of field and distortion. It is even more desirable that the upper limit is 0.80.

It is desirable that the lower limit of conditional formula (1.4) is 0.3. When the lower limit of conditional formula (14) is 0.3, it is possible to more easily correct curvature of field. It is more desirable that the lower limit of conditional formula (14) is 0.4 to correct curvature of field. It is even more desirable that the lower limit is 0.5.

Therefore, for example, it is desirable that the following conditional formula (14-1), (14-2) or (14-3) is satisfied: 0.3≦(R3+R4)/(R3−R4)≦0.9  (14-1); 0.4≦(R3+R4)/(R3−R4)≦0.85  (14-2); or 0.5≦(R3+R4)/(R3−R4)≦0.80  (14-3).

It is desirable that the upper limit of conditional formula (15) is −1.2. When the upper limit of conditional formula (15) is −1.2, it is possible to more easily correct curvature of field. It is more desirable that the upper limit of conditional formula (15) is −1.25 to more easily reduce the size of the lens system and to more easily correct curvature of field. It is even more desirable that the upper limit is −1.3.

It is desirable that the lower limit of conditional formula (15) is −8.5. When the lower limit of conditional formula (15) is −8.5, it is possible to more easily correct curvature of field and a lateral chromatic aberration. It is desirable that the lower limit of conditional formula (15) is −5 to more easily correct curvature of field and a lateral chromatic aberration. It is more desirable that the lower limit is −3.5.

Therefore, for example, it is desirable that the following conditional formula (15-1), (15-2) or (15-3) is satisfied: −8.5≦(R5+R6)/(R5−R6)≦−1.2  (15-1); −5≦(R5+R6)/(R5−R6)≦−1.25  (15-2); or −3.5≦(R5+R6)/(R5−R6)≦−1.3  (15-3).

It is desirable that the upper limit of conditional formula (16) is 2.5. When this upper limit is satisfied, it is possible to more easily widen the angle of view. It is desirable that the upper limit of conditional formula (16) is 2.0 to more easily widen the angle of view. It is more desirable that the upper limit is 1.82. It is even more desirable that the upper limit is 1.8.

It is desirable that the lower limit of conditional formula (16) is 1.2. When this lower limit is satisfied, it is possible to more easily correct distortion. Further, it is desirable that the lower limit of conditional formula (16) is 1.3. It is more desirable that the lower limit is 1.4. It is even more desirable that the lower limit is 1.43.

Therefore, for example, it is desirable that the following conditional formula (16-1), (16-2) or (16-3) is satisfied: 1.2≦(R1+R2)/(R1−R2)≦2.5  (16-1); 1.3≦(R1+R2)/(R1−R2)≦2.0  (16-2); or 1.4≦(R1+R2)/(R1−R2)≦1.8  (16-3).

It is desirable that the upper limit of conditional formula (17) is −1.5. When this upper limit is satisfied, it is possible to more easily correct curvature of field and a lateral chromatic aberration. It is desirable that the upper limit of conditional formula (17) is −1.7 to more easily correct curvature of field and a lateral chromatic aberration. It is more desirable that the upper limit is −1.8. It is even more desirable that the upper limit is −2.0.

It is desirable that the lower limit of conditional formula (17) is −4. When this lower limit is satisfied, it is possible to easily widen the angle of view and reduce the size of the lens system. It is desirable that the lower limit of conditional formula (17) is −3.5 to more easily widen the angle of view and reduce the size of the lens system. It is more desirable that the lower limit is −3.2.

Therefore, for example, it is desirable that the following conditional formula (17-1), (17-2) or (17-3) is satisfied: −4<f123/f<−1.5  (17-1); −3.5<f123/f<−1.7  (17-2); or −3.2<f123/f<−1.8  (17-3).

It is desirable that the upper limit of conditional formula (18) is 11. When this upper limit is satisfied, it is possible to easily correct curvature of field and a lateral chromatic aberration. It is desirable that the upper limit of conditional formula (18) is 10 to more easily correct curvature of field and a lateral chromatic aberration. It is more desirable that the upper limit is 8.

It is desirable that the lower limit of conditional formula (18) is 2.5. When this lower limit is satisfied, it is possible to more easily secure a back focus. It is desirable that the lower limit of conditional formula (18) is 3.0 to more easily secure the back focus. It is more desirable that the lower limit is 3.5.

Therefore, for example, it is desirable that the following conditional formula (18-1), (18-2) or (18-3) is satisfied: 2.5<f3/f<11  (18-1); 3.0<f3/f<10  (18-2); or 3.5<f3/f<10  (18-3).

It is desirable that the upper limit of conditional formula (19) is 0.3. When this upper limit is satisfied, it is possible to more easily correct chromatic aberrations and reduce the size of the lens system. It is desirable that the upper limit of conditional formula (19) is 0.25 to more easily correct chromatic aberrations and reduce the size of the lens system. It is more desirable that the upper limit is 0.2.

It is desirable that the lower limit of conditional formula (19) is 0.05. For example, when an aspherical surface is used as an image-side surface of fourth lens L4 or an object-side surface of fifth lens L5, if this lower limit is satisfied, it is possible to easily provide a long distance between surfaces. Therefore, the shape of the aspherical surface is more flexibly selectable. Further, correction of curvature of field and a spherical aberration becomes easy. It is more desirable that the lower limit of conditional formula (19) is 0.07.

Therefore, for example, it is desirable that the following conditional formula (19-1), (19-2) or (19-3) is satisfied: 0.05<D9/f<0.3  (19-1); 0.05<D9/f<0.25  (19-2); or 0.05<D9/f<0.2  (19-3).

It is desirable that the upper limit of conditional formula (20) is 3.5. When this upper limit is satisfied, it is possible to easily correct a longitudinal chromatic aberration and a lateral chromatic aberration. It is desirable that the upper limit of conditional formula (20) is 3.0 to more easily correct a longitudinal chromatic aberration and a lateral chromatic aberration. It is more desirable that the upper limit is 2.9. It is even more desirable that the upper limit is 2.8.

It is desirable that the lower limit of conditional formula (20) is 1.5. When this lower limit is satisfied, it is possible to easily secure a back focus. It is desirable that the lower limit of conditional formula (20) is 1.7 to more easily secure a back focus. It is more desirable that the lower limit is 1.8.

Therefore, for example, it is desirable that the following conditional formula (20-1), (20-2) or (20-3) is satisfied: 1.5<f4/f<3.0  (20-1); 1.7<f4/f<2.9  (20-2); or 1.8<f4/f<2.8  (20-3).

It is desirable that the upper limits of conditional formulas (21) and (21-1) are 7.0. When this upper limit is satisfied, it is possible to more easily reduce the effective diameter of first lens L1. It is desirable that the upper limits of conditional formulas (21) and (21-1) are 6.8 to further reduce the effective diameter of first lens L1. It is more desirable that the upper limits are 6.5.

It is desirable that the lower limits of conditional formulas (21) and (21-1) are 3.0. When this lower limit is satisfied, it is possible to more easily correct distortion and curvature of field. It is desirable that the lower limits of conditional formulas (21) and (21-1) are 3.5 to more easily correct distortion and curvature of field. It is more desirable that the lower limit is 4.0. It is even more desirable that the lower limit is 4.5.

Therefore, for example, it is desirable that the following conditional formula (21-2), (21-3) or (21-4) is satisfied: 3.0<ER1/f<7.0  (21-2); 3.5<ER1/f<6.8  (21-3); or 4.0<ER1/f<6.5  (21-4).

It is desirable that an aperture stop is arranged between third lens L3 and fourth lens L4. When the aperture stop is arranged between third lens L3 and fourth lens L4, it is possible to reduce the size of the whole system. If the aperture stop is located close to the object side, it is possible to easily reduce the outer diameter of first lens L1. However, if the aperture stop is too close to the object side, it becomes difficult to separate axial rays and off-axial rays from each other at first lens L1 and second lens L2. Further, it becomes difficult to correct curvature of field. When the aperture stop is arranged between third lens L3 and fourth lens L4, it is possible to easily correct curvature of field while reducing the lens diameter.

It is desirable that the Abbe numbers of the materials of first lens L1, second lens L2, fourth lens L4 and sixth lens L6 for d-line are greater than or equal to 40. Then, it is possible to suppress generation of chromatic aberrations, and to achieve excellent resolution performance. It is more desirable that the Abbe numbers are greater than or equal to 47.

It is desirable that the Abbe number of the material of second lens L2 for d-line is greater than or equal to 50. Then, it is possible to further suppress generation of chromatic aberrations, and to achieve excellent resolution performance. It is more desirable that the Abbe number is greater than or equal to 52.

It is desirable that the Abbe number of the material of sixth lens L6 for d-line is greater than or equal to 50. Then, it is possible to further suppress generation of chromatic aberrations, and to achieve excellent resolution performance. It is more desirable that the Abbe number is greater than or equal to 52.

It is desirable that the Abbe number of the material of third lens L3 for d-line is less than or equal to 40. Then, it is possible to excellently correct a lateral chromatic aberration. It is more desirable that the Abbe number is less than or equal to 30. It is even more desirable that the Abbe number is less than or equal to 28. It is still more desirable that the Abbe number is less than or equal to 25.

It is desirable that the Abbe number of the material of fifth lens L5 for d-line is less than or equal to 40. Then, it is possible to excellently correct a lateral chromatic aberration. It is more desirable that the Abbe number is less than or equal to 30. It is even more desirable that the Abbe number is less than or equal to 28. It is still more desirable that the Abbe number is less than or equal to 25. It is more desirable that the Abbe number is less than or equal to 20.

When the Abbe number of the material of first lens L1 for d-line is vd1, and the Abbe number of the material of second lens L2 for d-line is vd2, it is desirable that vd1/vd2 is greater than or equal to 0.7. Then, it is possible to suppress generation of chromatic aberrations, and to achieve excellent resolution performance. Further, it is more desirable that vd1/vd2 is greater than or equal to 0.8. It is desirable that vd1/vd2 is less than or equal to 1.2 to balance the Abbe number of first lens L1 and the Abbe number of second lens L2 and to suppress generation of chromatic aberrations.

When the Abbe number of the material of second lens L2 for d-line is vd2, and the Abbe number of the material of third lens L3 for d-line is vd3, it is desirable that vd2/vd3 is greater than or equal to 2.0. Then, it is possible to excellently correct a longitudinal chromatic aberration and a lateral chromatic aberration.

When the Abbe number of the material of first lens L1 for d-line is vd1, and the Abbe number of the material of third lens L3 for d-line is vd3, it is desirable that vd1/vd3 is greater than or equal to 1.8. Then, it is possible to easily correct a longitudinal chromatic aberration and a lateral chromatic aberration in an excellent manner. Further, it is more desirable that vd1/vd3 is greater than or equal to 1.9 to more excellently correct a longitudinal chromatic aberration and a lateral chromatic aberration.

When the Abbe number of the material of first lens L1 for d-line is vd1, and the Abbe number of the material of third lens L3 for d-line is vd3, it is desirable that vd1/vd3 is less than or equal to 2.5. Then, it is possible to prevent the Abbe number of third lens L3 from becoming too small, and to easily reduce the cost of the material of third lens L3. Or, it is possible to prevent the Abbe number of first lens L1 from becoming too large. Therefore, it is possible to easily increase the refractive power of first lens L1 by increasing the refractive index of first lens L1. Therefore, it is possible to easily reduce the size of the lens system and to easily correct distortion.

It is desirable that the refractive index of the material of first lens L1 for d-line is lower than or equal to 1.90. Then, it is possible to easily lower the cost of the material of first lens L1. Further, when the material having a low refractive index is used, a material having a large Abbe number becomes selectable. Therefore, correction of chromatic aberrations becomes easy. Further, it becomes possible to easily achieve excellent resolution performance. Further, it is more desirable that the refractive index is lower than or equal to 1.85 to more excellently correct chromatic aberrations. It is even more desirable that the refractive index is lower than or equal to 1.80.

It is desirable that the refractive index of the material of first lens L1 for d-line is higher than or equal to 1.60. Then, it is possible to easily increase the refractive power of first lens L1, and to easily widen the angle of view. Further, it becomes possible to easily correct distortion. Further, it is more desirable that the refractive index is higher than or equal to 1.65 to easily widen the angle of view and to easily correct distortion. It is even more desirable that the refractive index is higher than or equal to 1.70.

It is desirable that the refractive index of the material of second lens L2 for d-line is lower than or equal to 1.70. Then, it is possible to reduce the cost of the material of second lens L2. If the material has a high refractive index, the Abbe number becomes small. Therefore, chromatic aberrations increase, and it becomes difficult to achieve excellent resolution performance. It is more desirable that the refractive index is lower than or equal to 1.65 to reduce the cost of the material of second lens L2. It is even more desirable that the refractive index is lower than or equal to 1.60.

It is desirable that the refractive index of the material of second lens L2 for d-line is higher than or equal to 1.50. Then, it is possible to easily increase the refractive power of second lens L2, and to easily correct distortion. Further, since it is possible to easily increase the refractive power of second lens L2, it is possible to easily reduce the size of the lens system.

It is desirable that the refractive index of the material of third lens L3 for d-line is lower than or equal to 1.75. Then, it is possible to reduce the cost of the material of third lens L3. It is more desirable that the refractive index is lower than or equal to 1.70 to reduce the cost of the material of third lens L3. It is even more desirable that the refractive index is lower than or equal to 1.68. It is still more desirable that the refractive index is lower than or equal to 1.65.

It is desirable that the refractive index of the material of third lens L3 for d-line is higher than or equal to 1.50. Then, it is possible to easily increase the refractive power of third lens L3 by increasing the refractive index of the material of third lens L3, and to easily correct a lateral chromatic aberration and curvature of field. It is more desirable that the refractive index is higher or equal to 1.55 to increase the refractive index of third lens L3. It is more desirable that the refractive index is higher than or equal to 1.60. It is even more desirable that the refractive index is higher than or equal to 1.63.

It is desirable that the refractive index of the material of fourth lens L4 for d-line is lower than or equal to 1.80. Then, it is possible to reduce the cost of the material of fourth lens L4. Further, since it is possible to easily select a material with a large Abbe number, it is possible to easily correct chromatic aberrations, and to achieve excellent resolution performance.

It is desirable that the refractive index of the material of fourth lens L4 for d-line is higher than or equal to 1.50. Then, it is possible to easily increase the refractive power of fourth lens L4 by increasing the refractive index of the material of fourth lens L4. Since the refractive power of fourth lens L4 is increased, it is possible to easily correct a spherical aberration at fourth lens L4. Further, since it is possible to sharply bend rays at fourth lens L4, it is possible to easily suppress an angle at which peripheral rays enter an imaging device. Therefore, it is possible to easily suppress shading.

It is desirable that the refractive index of the material of fifth lens L5 for d-line is higher than or equal to 1.50. Then, it is possible to easily increase the refractive power of fifth lens L5 by increasing the refractive index of the material of fifth lens L5. Further, since it is possible to easily select a material with a large Abbe number, it is possible to easily correct chromatic aberrations, and to achieve excellent resolution performance. It is more desirable that the refractive index is higher than or equal to 1.55 to increase the refractive index of the material of fifth lens L5. It is even more desirable that the refractive index is higher than or equal to 1.60. It is still more desirable that the refractive index is higher than or equal to 1.63.

It is desirable that the refractive index of the material of sixth lens L6 for d-line is higher than or equal to 1.50. Then, it is possible to easily increase the refractive power of sixth lens L6 by increasing the refractive index of the material of sixth lens L6. Therefore, it is possible to easily correct a spherical aberration and to easily suppress an angle at which rays enter an imaging device. Therefore, it is possible to easily suppress shading. It is desirable that the refractive index of the material of sixth lens L6 for d-line is lower than or equal to 1.70. Then, it is possible to easily select a material with a large Abbe number. Therefore, it becomes possible to easily correct chromatic aberrations, and to easily achieve excellent resolution performance. It is desirable that the refractive index of the material of sixth lens L6 for d-line is lower than or equal to 1.60 to correct chromatic aberrations.

It is desirable that the object-side surface of second lens L2 is aspherical. Then, it is possible to easily reduce the size of the lens system, and to easily widen the angle of view, or excellent correction of curvature of field and distortion becomes easy. It is desirable that the object-side surface of second lens has a shape having negative refractive power at a center, and including a part having positive refractive power in an area between the center and an effective diameter edge, and having negative refractive power at the effective diameter edge. When the object-side surface of second lens L2 has such a shape, it is possible to reduce the size of the lens system, and to widen the angle of view. At the same time, it is possible to excellently correct curvature of field and distortion.

Here, the phrase “effective diameter of a surface” means the diameter of a circle composed of outermost points (points farthest from an optical axis) in the direction of the diameter when points of intersection of all rays contributing to image formation and a lens surface are considered. Further, the term “effective diameter edge” means the outermost points. When a system is rotationally symmetric with respect to an optical axis, a figure composed of the outermost points is a circle. However, when a system is not rotationally symmetric, a figure composed of the outermost points is not a circle in some cases. In such a case, an equivalent circle may be considered, and the diameter of the equivalent circle may be regarded as an effective diameter.

With respect to the shape of an aspherical surface, when a point on lens surface i (“i” is a sign representing a corresponding lens surface. For example, when the object-side surface of second lens L2 is represented by 3, “i” is considered as i=3 in the following descriptions about the object-side surface of second lens L2) of each lens is point Xi, and an intersection of a normal at the point and an optical axis is point Pi, a length of Xi−Pi (|Xi−Pi|) is defined as the absolute value |RXi| of a curvature radius at point Xi, and Pi is defined as the center of curvature at point Xi. Further, an intersection of the i-th lens surface and the optical axis is point Qi. At this time, refractive power at point Xi is defined based on whether point Pi is located on the object side or on the image side of point Qi. When point Xi is a point on the object-side surface, if point Pi is located on the image side of point Qi, refractive power at point Xi is defined as positive refractive power. If point Pi is located on the object side of point Qi, refractive power at point Xi is defined as negative refractive power. When point Xi is a point on the image-side surface, if point Pi is located on the object side of point Qi, refractive power at point Xi is defined as positive refractive power. If point Pi is located on the image side of point Qi, refractive power at point Xi is defined as negative refractive power.

When refractive power at the center and refractive power at point Xi are compared with each other, the absolute value of a curvature radius (a paraxial curvature radius) at the center and the absolute value |RXi| of a curvature radius at point Xi are compared with each other. If the value |RXi| is less than the absolute value of the paraxial curvature radius, refractive power at point Xi is regarded as being stronger than refractive power at the center. On the contrary, if the value |RXi| is greater than the absolute value of the paraxial curvature radius, refractive power at point Xi is regarded as being weaker than refractive power at the center. This relationship is similar whether a surface has positive refractive power or negative refractive power.

Here, with reference to FIG. 2, the shape of the object-side surface of second lens L2 will be described. FIG. 2 is a diagram illustrating optical paths of the imaging lens 1 illustrated in FIG. 1. In FIG. 2, point Q3 is the center of the object-side surface of second lens L2, which is an intersection of the object-side surface of second lens L2 and optical axis Z. In FIG. 2, point X3 on the object-side surface of second lens L2 is located at an effective diameter edge, and point X3 is an intersection of an outermost ray 6 included in off-axial rays 3 and the object-side surface of second lens L2. In FIG. 2, point X3 is located at the effective diameter edge. However, since point X3 is an arbitrary point on the object-side surface of second lens, other points may be considered in a similar manner.

At this time, an intersection of a normal to the lens surface at point X3 and optical axis Z is point P3, as illustrated in FIG. 2, and segment X3−P3 connecting point X3 and point P3 is defined as curvature radius RX3 at point X3, and the length |X3−P3| of segment X3−P3 is defined as absolute value |RX3| of curvature radius RX3. In other words, |X3−P3|=|RX3|. Further, a curvature radius at point Q3, in other words, a curvature radius at the center of the object-side surface of second lens L2 is R3, and the absolute value of the curvature radius is |R3| (not illustrated in FIG. 2).

The expression “a shape having negative refractive power at a center, and including a part having positive refractive power in an area between the center and an effective diameter edge” of the object-side surface of second lens L2 means a shape in which a paraxial region including point Q3 is concave, and in which point X3 with point P3 located on the image side of point Q3 is present between the center and the effective diameter edge. Further, the expression “a shape having negative refractive power at an effective diameter edge” of second lens L2 means a shape in which point P3 is located on the object side of point Q3 when point X3 is located at the effective diameter edge.

The object-side surface of second lens L2 may have a shape having negative refractive power both at the center and at the effective diameter edge, and when the negative refractive power at the center and the negative refractive power at the effective diameter edge are compared with each other, the negative refractive power at the effective diameter edge may be weaker than the negative refractive power at the center. When the object-side surface of second lens L2 has such a shape, it is possible to reduce the size of the lens system, and to widen the angle of view. At the same time, it is possible to excellently correct curvature of field.

The expression “a shape having negative refractive power both at the center and at the effective diameter edge, and when the negative refractive power at the center and the negative refractive power at the effective diameter edge are compared with each other, the negative refractive power at the effective diameter edge is weaker than the negative refractive power at the center” of the object-side surface of second lens L2 means a shape in which a paraxial region including point Q3 is concave, and in which point P3 is located on the object side of point Q3 when point X3 is located at the effective diameter edge, and in which the absolute value |RX3| of a curvature radius at point X3 is greater than the absolute value |R3| of a curvature radius at point Q3.

In FIG. 2, for the purpose of understanding, circle CQ3, which passes point Q3 with the radius of |R3|, and the center of which is a point on an optical axis, is drawn with a two dot dashed line. Further, a part of circle CX3, which passes point X3 with the radius of |RX3|, and the center of which is a point on the optical axis, is drawn with a broken line. Circle CX3 is larger than circle CQ3, and |R3|<|RX3| is clearly illustrated.

It is desirable that the image-side surface of second lens L2 is aspherical. Then, it is possible to excellently correct curvature of field and distortion. The image-side surface of second lens L2 may have a shape having negative refractive power both at the center and at a point of 50% of an effective diameter, and the negative refractive power at the point of 50% of the effective diameter may be stronger than the negative refractive power at the center. When the image-side surface of second lens L2 has such a shape, it is possible to excellently correct curvature of field and distortion. The phrase “a point of 50% of an effective diameter” means a point on a lens surface, the coordinate of which in the diameter direction of the lens surface (a coordinate in a direction perpendicular to an optical axis) is a distance of 50% of the effective diameter of the lens from the center of the lens.

The shape of the image-side surface of second lens L2 may be considered, as follows, in a manner similar to the shape of the object-side surface of second lens L2 explained with reference to FIG. 2. In a lens cross section, when a point on the image-side surface of second lens L2 is point X4, and an intersection of a normal at the point and optical axis Z is point P4, segment X4−P4 connecting point X4 and point P4 is defined as a curvature radius at point X4, and the length |X4−P4| of the segment connecting point X4 and point P4 is defined as absolute value |RX4| of the curvature radius at point X4. Therefore, |X4−P4|=|RX4|. Further, an intersection of the image-side surface of second lens L2 and optical axis Z, in other words, the center of the image-side surface of second lens L2 is point Q4, and the absolute value of a curvature radius at point Q4 is |R4|. For the purpose of explanation, when point X4 is a point of 50% of an effective diameter on the image-side surface of second lens L2, the point is referred to as point X4′. When point X4 is located at an effective diameter edge on the image-side surface of second lens L2, the point is referred to as point X4″. Similarly, the mark “′” and the mark “″” are attached also to other signs, such as “|RX4|”, to represent them by signs, such as |RX4′| and |RX4″|.

The expression “a shape having negative refractive power both at the center and at a point of 50% of an effective diameter, and the negative refractive power at the point of 50% of the effective diameter is stronger than the negative refractive power at the center” of the image-side surface of second lens L2 means that when a point of 50% of an effective diameter on the image-side surface of second lens L2 is point X4′, and an intersection of a normal at the point and optical axis Z is point P4′ in a lens cross section, a paraxial region including point Q4 is concave, and point P4′ is located on the image side of point Q4, and absolute value |RX4′| of a curvature radius at point X4′ is less than absolute value |R4| of a curvature radius at point Q4.

Further, when the refractive power at a point of 50% of the effective diameter on the image-side surface of second lens L2 and the refractive power at the effective diameter edge on the image-side surface of second lens L2 are compared with each other, the image-side surface of second lens L2 may have a shape in which the refractive power at the effective diameter edge is weaker than the refractive power at the point of 50% of the effective diameter. When the image-side surface of second lens L2 has such a shape, it is possible to excellently correct curvature of field and distortion.

The expression “a shape in which the refractive power at the effective diameter edge is weaker than the refractive power at the point of 50% of the effective diameter” means a shape in which absolute value |RX4″| of a curvature radius at point X4″ is greater than absolute value |RX4′| of a curvature radius at point X4′ when point X4″ is located at the effective diameter edge.

It is desirable that the image-side surface of second lens L2 has a shape having negative refractive power both at a point of 50% of the effective diameter and at the effective diameter edge. Then, it is possible to easily correct curvature of field and distortion. The expression “a shape having negative refractive power both at a point of 50% of the effective diameter and at the effective diameter edge” of the image-side surface of second lens L2 means a shape in which both of point P4′ and point P4″ are located on the image side of point Q4.

Second lens L2 may be a biconcave lens. Then, it is possible to easily correct curvature of field and distortion while reducing the size of the lens system and achieving a wide angle of view.

It is desirable that the object-side surface of third lens L3 is aspherical. It is desirable that the object-side surface of third lens L3 has a shape having positive refractive power both at the center and at the effective diameter edge, and the positive refractive power at the effective diameter edge being stronger than the positive refractive power at the center. When the object-side surface of third lens L3 has such a shape, it is possible to excellently correct curvature of field and a lateral chromatic aberration.

The shape of the object-side surface of third lens L3 may be considered, as follows, in a manner similar to the shape of the object-side surface of second lens L2 explained with reference to FIG. 2. In a lens cross section, when a point on the object-side surface of third lens L3 is point X5, and an intersection of a normal at the point and optical axis Z is point P5, segment X5−P5 connecting point X5 and point P5 is defined as a curvature radius at point X5, and the length |X5−P5| of the segment connecting point X5 and point P5 is defined as absolute value |RX5| of the curvature radius at point X5. Therefore, |X5−P5|=|RX5|. Further, an intersection of the object-side surface of third lens L3 and optical axis Z, in other words, the center of the object-side surface of third lens L3 is point Q5, and the absolute value of a curvature radius at point Q5 is |R5|.

The expression “a shape having positive refractive power both at the center and at the effective diameter edge, and the positive refractive power at the effective diameter edge being stronger than the positive refractive power at the center” of the object-side surface of third lens L3 means a shape in which a paraxial region including point Q5 is convex, and in which point P5 is located on the image side of point Q5 when point X5 is located at the effective diameter edge, and in which the absolute value |RX5| of a curvature radius at point X5 is less than the absolute value |R5| of a curvature radius at point Q5.

It is desirable that the image-side surface of third lens L3 is aspherical. It is desirable that the image-side surface of third lens L3 has a shape having negative refractive power both at the center and at the effective diameter edge, and the negative refractive power at the effective diameter edge being stronger than the negative refractive power at the center, or a shape having a flat surface at the center and negative refractive power at the effective diameter edge. When third lens L3 has such a shape, it is possible to excellently correct curvature of field.

The shape of the image-side surface of third lens L3 may be considered, as follows, in a manner similar to the shape of the object-side surface of second lens L2 explained with reference to FIG. 2. In a lens cross section, when a point on the image-side surface of third lens L3 is point X6, and an intersection of a normal at the point and optical axis Z is point P6, segment X6−P6 connecting point X6 and point P6 is defined as a curvature radius at point X6, and the length |X6−P6| of the segment connecting point X6 and point P6 is defined as absolute value |RX6| of the curvature radius at point X6. Therefore, |X6−P6|=|RX6|. Further, an intersection of the image-side surface of third lens L3 and optical axis Z, in other words, the center of the image-side surface of third lens L3 is point Q6, and the absolute value of a curvature radius at point Q6 is |R6|.

The expression “a shape having negative refractive power both at the center and at the effective diameter edge, and the negative refractive power at the effective diameter edge being stronger than the negative refractive power at the center” of the image-side surface of third lens L3 means a shape in which a paraxial region including point Q6 is concave, and in which point P6 is located on the image side of point Q6 when point X6 is located at the effective diameter edge, and in which the absolute value |RX6| of a curvature radius at point X6 is less than the absolute value |R6| of a curvature radius at point Q6.

Further, the expression “a shape having a flat surface at the center and negative refractive power at the effective diameter edge” means a shape in which a paraxial region including point Q6 is a flat surface, and point P6 is located on the image side of point Q6 when point X6 is located at the effective diameter edge.

It is desirable that the object-side surface of fourth lens L4 is aspherical. It is desirable that the object-side surface of fourth lens L4 has a shape having positive refractive power both at the center and at the effective diameter edge, and the positive refractive power at the effective diameter edge being weaker than the positive refractive power at the center, or a shape having positive refractive power at the center and negative refractive power at the effective diameter edge. When fourth lens L4 has such a shape, it is possible to excellently correct a spherical aberration and curvature of field.

The shape of the object-side surface of fourth lens L4 may be considered, as follows, in a manner similar to the shape of the object-side surface of second lens L2 explained with reference to FIG. 2. In a lens cross section, when a point on the object-side surface of fourth lens L4 is point X8, and an intersection of a normal at the point and optical axis Z is point P8, segment X8−P8 connecting point X8 and point P8 is defined as a curvature radius at point X8, and the length |X8−P8| of the segment connecting point X8 and point P8 is defined as absolute value |RX8| of the curvature radius at point X8. Therefore, |X8−P8|=|RX8|. Further, an intersection of the object-side surface of fourth lens L4 and optical axis Z, in other words, the center of the object-side surface of fourth lens L4 is point Q8, and the absolute value of a curvature radius at point Q8 is |R8|.

The expression “a shape having positive refractive power both at the center and at the effective diameter edge, and the positive refractive power at the effective diameter edge being weaker than the positive refractive power at the center” of the object-side surface of fourth lens L4 means a shape in which a paraxial region including point Q8 is convex, and in which point P8 is located on the image side of point Q8 when point X8 is located at the effective diameter edge, and in which the absolute value |RX8| of a curvature radius at point X8 is greater than the absolute value |R8| of a curvature radius at point Q8.

Further, the expression “a shape having positive refractive power at the center and negative refractive power at the effective diameter edge” means a shape in which a paraxial region including point Q8 is convex, and point P8 is located on the object side of point Q8 when point X8 is located at the effective diameter edge.

It is desirable that the image-side surface of fourth lens L4 is aspherical. It is desirable that the image-side surface of fourth lens L4 has a shape having positive refractive power both at the center and at the effective diameter edge, and the positive refractive power at the effective diameter edge being weaker than the positive refractive power at the center. When fourth lens L4 has such a shape, it is possible to excellently correct a spherical aberration, curvature of field and distortion.

The shape of the image-side surface of fourth lens L4 may be considered, as follows, in a manner similar to the shape of the object-side surface of second lens L2 explained with reference to FIG. 2. In a lens cross section, when a point on the image-side surface of fourth lens L4 is point X9, and an intersection of a normal at the point and optical axis Z is point P9, segment X9−P9 connecting point X9 and point P9 is defined as a curvature radius at point X9, and the length |X9−P9| of the segment connecting point X9 and point P9 is defined as absolute value |RX9| of the curvature radius at point X9. Therefore, |X9−P9|=|RX9|. Further, an intersection of the image-side surface of fourth lens L4 and optical axis Z, in other words, the center of the image-side surface of fourth lens L4 is point Q9, and the absolute value of a curvature radius at point Q9 is |R9|.

The expression “a shape having positive refractive power both at the center and at the effective diameter edge, and the positive refractive power at the effective diameter edge being weaker than the positive refractive power at the center” of the image-side surface of fourth lens L4 means a shape in which a paraxial region including point Q9 is convex, and in which point P9 is located on the object side of point Q9 when point X9 is located at the effective diameter edge, and in which the absolute value |RX9| of a curvature radius at point X9 is greater than the absolute value |R9| of a curvature radius at point Q9.

It is desirable that the object-side surface of fifth lens L5 is aspherical. It is desirable that the object-side surface of fifth lens L5 has a shape having negative refractive power both at the center and at the effective diameter edge, and the negative refractive power at the effective diameter edge being stronger than the negative refractive power at the center. When fifth lens L5 has such a shape, it is possible to excellently correct a spherical aberration and curvature of field.

The shape of the object-side surface of fifth lens L5 may be considered, as follows, in a manner similar to the shape of the object-side surface of second lens L2 explained with reference to FIG. 2. In a lens cross section, when a point on the object-side surface of fifth lens L5 is point X10, and an intersection of a normal at the point and optical axis Z is point P10, segment X10−P10 connecting point X10 and point P10 is defined as a curvature radius at point X10, and the length |X10−P10| of the segment connecting point X10 and point P10 is defined as absolute value |RX10| of the curvature radius at point X10. Therefore, |X10−P10|=|RX10|. Further, an intersection of the object-side surface of fifth lens L5 and optical axis Z, in other words, the center of the object-side surface of fifth lens L5 is point Q10, and the absolute value of a curvature radius at point Q10 is |R10|.

The expression “a shape having negative refractive power both at the center and at the effective diameter edge, and the negative refractive power at the effective diameter edge being stronger than the negative refractive power at the center” of the object-side surface of fifth lens L5 means a shape in which a paraxial region including point Q10 is concave, and in which point P10 is located on the object side of point Q10 when point X10 is located at the effective diameter edge, and in which the absolute value |RX10| of a curvature radius at point X10 is less than the absolute value |R10| of a curvature radius at point Q10.

When fifth lens L5 is a biconcave lens, it is desirable that the object-side surface of fifth lens L5 has a shape having negative refractive power both at the center and at the effective diameter edge, and the negative refractive power at the effective diameter edge being stronger than the negative refractive power at the center. When the object-side surface of fifth lens L5 has such a shape, it is possible to excellently correct a spherical aberration and curvature of field.

The object-side surface of fifth lens L5 may have a shape having negative refractive power both at the center and at the effective diameter edge, and the negative refractive power at the effective diameter edge being weaker than the negative refractive power at the center. When fifth lens L5 has such a shape, it is possible to excellently correct curvature of field.

The expression “a shape having negative refractive power both at the center and at the effective diameter edge, and the negative refractive power at the effective diameter edge being weaker than the negative refractive power at the center” of the object-side surface of fifth lens L5 means a shape in which a paraxial region including point Q10 is concave, and in which point P10 is located on the object side of point Q10 when point X10 is located at the effective diameter edge, and in which the absolute value |RX10| of a curvature radius at point X10 is greater than the absolute value |R10| of a curvature radius at point Q10.

It is desirable that the image-side surface of fifth lens L5 is aspherical. It is desirable that the image-side surface of fifth lens L5 has a shape having negative refractive power both at the center and at the effective diameter edge, and the negative refractive power at the effective diameter edge being weaker than the negative refractive power at the center. When fifth lens L5 has such a shape, it is possible to excellently correct curvature of field.

The shape of the image-side surface of fifth lens L5 may be considered, as follows, in a manner similar to the shape of the object-side surface of second lens L2 explained with reference to FIG. 2. In a lens cross section, when a point on the image-side surface of fifth lens L5 is point X11, and an intersection of a normal at the point and optical axis Z is point P11, segment X11−P11 connecting point X11 and point P11 is defined as a curvature radius at point X11, and the length |X11−P11| of the segment connecting point X11 and point P11 is defined as absolute value |RX11| of the curvature radius at point X11. Therefore, |X11|−P11|=|RX11|. Further, an intersection of the image-side surface of fifth lens L5 and optical axis Z, in other words, the center of the image-side surface of fifth lens L5 is point Q11, and the absolute value of a curvature radius at point Q11 is |R11|.

The expression “a shape having negative refractive power both at the center and at the effective diameter edge, and the negative refractive power at the effective diameter edge being weaker than the negative refractive power at the center” of the image-side surface of fifth lens L4 means a shape in which a paraxial region including point Q11 is concave, and in which point P11 is located on the image side of point Q11 when point X11 is located at the effective diameter edge, and in which the absolute value |RX1| of a curvature radius at point X11 is greater than the absolute value |R11| of a curvature radius at point Q11.

When fifth lens L5 is a biconcave lens, it is desirable that the image-side surface of fifth lens L5 has a shape having negative refractive power both at the center and at the effective diameter edge, and the negative refractive power at the effective diameter edge being weaker than the negative refractive power at the center. When the image-side surface of fifth lens L5 has such a shape, it is possible to excellently correct curvature of field while excellently correcting chromatic aberrations between fifth lens L5 and sixth lens L6.

When fifth lens L5 has a meniscus shape with a concave surface facing the object side, it is desirable that the object-side surface of fifth lens L5 has a negative shape having negative refractive power both at the center and at the effective diameter edge, and the negative refractive power at the effective diameter edge being weaker than the negative refractive power at the center. When the object-side surface of fifth lens L5 has such a shape, it is possible to easily correct a longitudinal chromatic aberrations between fourth lens L4 and fifth lens L5. Further, it is possible to easily correct curvature of field.

When fifth lens L5 has a meniscus shape with a concave surface facing the object side, it is desirable that the image-side surface of fifth lens L5 has a positive shape having positive refractive power both at the center and at the effective diameter edge, and the positive refractive power at the effective diameter edge being weaker than the positive refractive power at the center. When the image-side surface of fifth lens L5 has such a shape, it is possible to easily correct a spherical aberrations in an excellent manner.

When fifth lens L5 has a meniscus shape with a concave surface facing the object side, the image-side surface of fifth lens L5 may have a positive shape having positive refractive power both at the center and at the effective diameter edge, and the positive refractive power at the effective diameter edge being stronger than the positive refractive power at the center. When the image-side surface of fifth lens L5 has such a shape, it is possible to easily correct curvature of field in an excellent manner.

It is desirable that sixth lens L6 is a biconvex lens. When sixth lens L6 has such a shape, it is possible to easily increase the refractive power of sixth lens L6, and to suppress an angle at which rays enter an imaging device. Therefore, it is possible to suppress shading.

It is desirable that the object-side surface of sixth lens L6 is aspherical. It is desirable that the object-side surface of sixth lens L6 has a shape having positive refractive power both at the center and at the effective diameter edge, and the positive refractive power at the effective diameter edge being weaker than the positive refractive power at the center. When the object-side surface of sixth lens L6 has such a shape, it is possible to easily correct curvature of field and a spherical aberration in an excellent manner.

The shape of the object-side surface of sixth lens L6 may be considered, as follows, in a manner similar to the shape of the object-side surface of second lens L2 explained with reference to FIG. 2. In a lens cross section, when a point on the object-side surface of sixth lens L6 is point X12, and an intersection of a normal at the point and optical axis Z is point P12, segment X12−P12 connecting point X12 and point P12 is defined as a curvature radius at point X12, and the length |X12−P12| of the segment connecting point X12 and point P12 is defined as absolute value |RX12| of the curvature radius at point X12. Therefore, |X12−P12|=|RX12|. Further, an intersection of the object-side surface of sixth lens L6 and optical axis Z, in other words, the center of the object-side surface of sixth lens L6 is point Q12, and the absolute value of a curvature radius at point Q12 is |R12|.

The expression “a shape having positive refractive power both at the center and at the effective diameter edge, and the positive refractive power at the effective diameter edge being weaker than the positive refractive power at the center” of the object-side surface of sixth lens L6 means a shape in which a paraxial region including point Q12 is convex, and in which point P12 is located on the image side of point Q12 when point X12 is located at the effective diameter edge, and in which the absolute value |RX12| of a curvature radius at point X12 is greater than the absolute value |R12| of a curvature radius at point Q12.

When sixth lens L6 is a biconvex lens, it is desirable that the object-side surface of sixth lens L6 has a shape having positive refractive power at the center and weaker positive refractive power at the effective diameter edge, compared with the center. When sixth lens L6 is a biconvex lens, if the object-side surface of sixth lens L6 has such a shape, it is possible to easily correct curvature of field and a spherical aberration in an excellent manner.

Sixth lens L6 may have a meniscus shape with a convex surface facing the image side. When sixth lens L6 has such a shape, it is possible to easily correct curvature of field in an excellent manner.

It is desirable that the object-side surface of sixth lens L6 is aspherical. It is desirable that the object-side surface of sixth lens L6 has a shape having negative refractive power at the center and a part having positive refractive power between a point of 50% of an effective diameter and a point of 80% of the effective diameter. When the object-side surface of sixth lens L6 has such a shape, it is possible to easily correct curvature of field in an excellent manner. The phrase “a point of 80% of the effective diameter” means a point on a lens surface, the coordinate of which in the diameter direction of the lens surface (a coordinate in a direction perpendicular to an optical axis) is a distance of 80% of the effective diameter of the lens from the center of the lens.

The expression “a shape having negative refractive power at the center and a part having positive refractive power between a point of 50% of an effective diameter and a point of 80% of the effective diameter” of the object-side surface of sixth lens L6 means that a paraxial region including point Q12 is concave, and that point X12 at which point P12 is located on the image side of point Q12 is present between a point of 50% of an effective diameter and a point of 80% of the effective diameter.

It is desirable that the object-side surface of sixth lens L6 is aspherical. It is desirable that the object-side surface of sixth lens L6 has a shape having negative refractive power at the center, a part having positive refractive power between a point of 50% of an effective diameter and a point of 80% of the effective diameter, and negative refractive power at the effective diameter edge. When the object-side surface of sixth lens L6 has such a shape, it is possible to easily correct curvature of field in an excellent manner.

For the purpose of explanation, when point X12 is located at an effective diameter edge on the object-side surface of sixth lens L6, the mark “″” is attached to each sign to represent them by point “X12″” or the like.

The expression “a shape having negative refractive power at the center, a part having positive refractive power between a point of 50% of an effective diameter and a point of 80% of the effective diameter, and negative refractive power at the effective diameter edge” of the object-side surface of sixth lens L6 means that a paraxial region including point Q12 is concave when a point at the effective diameter edge on the object-side surface of sixth lens L6 is point X12″ and an intersection of a normal at the point and optical axis Z is point P12″, and that point X12 at which point P12 is located on the image side of point Q12 is present between a point of 50% of an effective diameter and a point of 80% of the effective diameter, and that point P12″ is located on the object side of point Q12.

It is desirable that the image-side surface of sixth lens L6 is aspherical. It is desirable that the image-side surface of sixth lens L6 has a shape having positive refractive power both at the center and at the effective diameter edge, and the positive refractive power at the effective diameter edge being weaker, compared with the center, or a shape having positive refractive power at the center and negative refractive power at the effective diameter edge. When the image-side surface of sixth lens L6 has such a shape, it is possible to excellently correct a spherical aberration and curvature of field.

The shape of the image-side surface of sixth lens L6 may be considered, as follows, in a manner similar to the shape of the object-side surface of second lens L2 explained with reference to FIG. 2. In a lens cross section, when a point on the image-side surface of sixth lens L6 is point X13, and an intersection of a normal at the point and optical axis Z is point P13, segment X13−P13 connecting point X13 and point P13 is defined as a curvature radius at point X13, and the length |X13−P13| of the segment connecting point X13 and point P13 is defined as absolute value |RX13| of the curvature radius at point X13. Therefore, |X13−P13|=|RX13|. Further, an intersection of the image-side surface of sixth lens L6 and optical axis Z, in other words, the center of the image-side surface of sixth lens L6 is point Q13, and the absolute value of a curvature radius at point Q13 is |R13|.

The expression “a shape having positive refractive power both at the center and at the effective diameter edge, and the positive refractive power at the effective diameter edge being weaker, compared with the center” of the image-side surface of sixth lens L6 means a shape in which a paraxial region including point Q13 is convex, and in which point P13 is located on the object side of point Q13 when point X13 is located at the effective diameter edge, and in which the absolute value |RX13| of a curvature radius at point X13 is greater than the absolute value |R13| of a curvature radius at point Q13.

Further, the expression “a shape having positive refractive power at the center and negative refractive power at the effective diameter edge” means a shape in which a paraxial region including point Q13 is convex, and in which point P13 is located on the image side of point Q13 when point X13 is located at the effective diameter edge.

When each surface of the object-side surface of second lens L2 through the image-side surface of sixth lens L6 has an aspherical shape as described above, it is possible to excellently correct distortion in addition to a spherical aberration, curvature of field and a coma aberration.

It is desirable that first lens L1 is a meniscus lens with a convex surface facing the object side. Then, it becomes possible to produce a wide angle lens, for example, exceeding 180 degrees. When first lens L1 is a biconcave lens, it is possible to easily increase the refractive power of first lens L1. Therefore, it is possible to easily widen an angle of view. However, rays are sharply bent by first lens L1. Therefore, correction of distortion becomes difficult. Further, when the object-side surface is a concave surface, an angle of incidence of peripheral rays entering the lens surface becomes large. Therefore, when rays enter the surface, a reflection loss becomes large. Hence, a peripheral area becomes dark. Further, when an angle of incidence of a ray exceeds 180 degrees, the ray cannot enter the surface. Therefore, it is desirable that first lens L1 is a positive meniscus lens having a convex surface facing the object side to easily correct distortion while achieving a wide angle of view.

It is desirable that second lens L2 is a biconcave lens. When second lens L2 is a biconcave lens, it becomes possible to easily widen an angle of view, and to easily correct curvature of field, distortion and a spherical aberration.

It is desirable that third lens L3 has a meniscus shape with a convex surface facing the object side. Then, it is possible to easily reduce the size of the lens system in the direction of the system. Further, it is possible to excellently correct curvature of field and a coma aberration.

It is desirable that fourth lens L4 is a biconvex lens. Then, it is possible to excellently correct a spherical aberration and curvature of field. Further, it is possible to easily correct chromatic aberrations between fourth lens L4 and fifth lens L5 by increasing the refractive power of fourth lens L4.

Fifth lens L5 may be a negative meniscus lens with a convex surface facing the image side, or a plano-concave lens with a flat surface facing the image side. Then, it is possible to easily correct a coma aberration and curvature of field in an excellent manner.

Fifth lens L5 may be a plano-concave lens with a concave surface facing the object side, or a biconcave lens. Then, it is possible to easily correct chromatic aberrations in cooperation with fourth lens L4 by increasing the refractive power of fifth lens L5.

It is desirable that sixth lens L6 is a biconvex lens. Then, it is possible to suppress an angle at which rays enter an imaging device. Therefore, it is possible to easily suppress shading.

Sixth lens L6 may be a meniscus lens with a convex surface facing the image side. Then, it is possible to easily correct curvature of field in an excellent manner.

It is desirable that the material of first lens L1 is glass. When an imaging lens is used in tough environment conditions, for example, such as use in an in-vehicle camera or a surveillance camera, first lens L1, which is arranged on the most object side, needs to use a material resistant to a deterioration of a surface by wind and rain and a change in temperature by direct sun light, and resistant to chemicals, such as oils and fats and detergents. In other words, the material needs to be highly water-resistant, weather-resistant, acid-resistant, chemical-resistant, and the like. Further, in some cases, the material needs to be hard and not easily breakable. If the material of first lens L1 is glass, it is possible to satisfy such needs. Alternatively, transparent ceramic may be used as the material of first lens L1.

One or both of the surfaces of first lens L1 may be aspherical. When first lens L1 is a glass aspheric lens, it is possible to more excellently correct various aberrations.

Further, a protection means may be applied to the object-side surface of first lens L1 to increase the strength, scratch-resistance, and chemical-resistance of the surface. In that case, the material of first lens L1 may be plastic. The protection means may be a hard coating or a water-repellent coating.

It is desirable that a material of one of second lens L2, third lens L3 and sixth lens L6, or materials of arbitrary plural lenses of them in combination are plastic. When the material is plastic, it is possible to structure the lens system at low cost and with light weight. Further, when an aspherical surface is provided, it is possible to accurately produce the aspherical shape. Therefore, it is possible to produce a lens having excellent performance.

The material of at least one of fourth lens L4 and fifth lens L5 may be plastic. When the material is plastic, it is possible to structure the lens system at low cost and with light weight. Further, when an aspherical surface is provided, it is possible to accurately produce the aspherical shape. Therefore, it is possible to produce a lens having excellent performance.

It is desirable that the materials of second lens L2, fourth lens L4 and sixth lens L6 are polyolefin. Polyolefin can produce a material having a low water absorption ratio, high transparency, low double refraction, and a large Abbe number. When the material of second lens L2 is polyolefin, it is possible to produce a lens a change in the shape of which by absorption of water is small, and which has high transmission and low double refraction. Further, since it is possible to use the material having a large Abbe number, it is possible to suppress generation of a longitudinal chromatic aberration and a lateral chromatic aberration. Further, it is possible to produce a highly environment-resistant lens having excellent resolution performance.

It is desirable that the materials of third lens L3 and fifth lens L5 are polycarbonate. Polycarbonate has a small Abbe number. When polycarbonate is used in third lens L3, it is possible to excellently correct a lateral chromatic aberration.

The materials of second lens L2 and fourth lens L4 may be acrylic. Since acrylic is inexpensive, it is possible to lower the cost of the lens system by using acrylic.

When plastic material is used in at least one of second lens L2, third lens L3, fourth lens L4, fifth lens L5 and sixth lens L6, so-called nano composite material, in which particles smaller than the wavelength of light are mixed into plastic, may be used as the material.

A material of one of second lens L2, third lens L3 and sixth lens L6, or materials of arbitrary plural lenses of them in combination may be glass. When the material is glass, it is possible to suppress a deterioration of performance caused by a change in temperature.

It is desirable that a material of at least one of fourth lens L4 and fifth lens L5 is glass. When the material of fourth lens L4 is glass, it is possible to suppress a deterioration of performance caused by a change in temperature. When the material of fifth lens L5 is glass, it is possible to easily select a material with a small Abbe number. Hence, it is possible to easily correct chromatic aberrations.

It is desirable that a glass transition temperature (Tg) of the material of at least one of first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5 and sixth lens L6 is higher than or equal to 145° C., and higher than or equal to 150° C. is more desirable. When a material the glass transition temperature of which is higher than or equal to 150° C. is used, it is possible to produce a lens having excellent heat-resistant characteristics.

Further, a filter that cuts ultraviolet light through blue light, or an IR (InfraRed) cut filter, which cuts infrared light, may be inserted between the lens system and the imaging device 5 based on the usage of the imaging lens 1. Alternatively, a coating having properties similar to those of the aforementioned filter may be applied to a lens surface, or a material that absorbs ultraviolet light, blue light, infrared light or the like may be used as the material of one of the lenses.

FIG. 1 illustrates a case in which optical member PP, which is assumed to be various filters or the like, is arranged between a lens system and the imaging device 5. Instead, the various filters may be arranged between lenses. Alternatively, a coating having an action similar to that of the various filters may be applied to a lens surface of one of the lenses included in the imaging lens.

Here, rays of light passing through the outside of the effective diameter between lenses may become stray light, and reach the image plane. Further, the stray light may become ghost. Therefore, it is desirable that a light shield means for blocking the stray light is provided, if necessary. The light shield means may be provided, for example, by applying an opaque paint to a portion of a lens outside the effective diameter, or by providing there an opaque plate member. Alternatively, an opaque plate member, as a light shield means, may be provided in the optical path of rays that will become stray light. Alternatively, a hood-like member for blocking stray light may be provided further on the object side of the most object-side lens. FIG. 1 illustrates an example in which light shield means 11, 12 are provided outside the effective diameter on the image-side surface of first lens L1 and on the image-side surface of fifth lens L5, respectively. The position at which the light shield means is provided is not limited to the example illustrated in FIG. 1. The light shield means may be arranged on another lens or between lenses.

Further, a member, such as a stop, may be arranged between lenses to block peripheral rays in such a manner that relative illumination is within a practically acceptable range. The peripheral rays are rays from an object point that is not on optical axis Z, and pass through the peripheral portion of the entrance pupil of an optical system. When a member that blocks the peripheral rays is provided in this manner, it is possible to improve the image quality in the peripheral portion of the image formation area. Further, the member can reduce ghost by blocking light that generates the ghost.

In the imaging lenses according to the first through third embodiments, it is desirable that the lens system consists of only six lenses of first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5 and sixth lens L6. When the lens system consists of only six lenses, it is possible to lower the cost of the lens system.

An imaging apparatus according to an embodiment of the present invention includes the imaging lens according to an embodiment of the present invention. Therefore, it is possible to structure the imaging apparatus in small size and at low cost. Further, the imaging apparatus has a sufficiently wide angle of view, and can obtain an excellent image with high resolution by using an imaging device.

An image obtained by photography using an imaging apparatus including the imaging lens according to the first through third embodiments may be displayed on a cellular phone. For example, a photography apparatus including the imaging lens according to an embodiment of the present invention is installed in a car as an in-vehicle camera in some cases. Further, the rear side of the car or a surrounding area of the car is photographed by the in-vehicle camera, and an image obtained by photography is displayed on a display device. In such a case, if a car navigation system (hereinafter, referred to as car navigation) is installed in the car, the image obtained by photography may be displayed on a display device of the car navigation. However, if a car navigation is not installed in the car, a specialized display device, such as a liquid crystal display, needs to be set in the car. However, a display device is expensive. Meanwhile, in recent years, a high performance display device, which can be used to browse dynamic images and the Web, became mounted on a cellular phone. If the cellular phone is used as a display device for an in-vehicle camera, even if a car navigation is not installed in the car, it is not necessary to install a specialized display device in the car. Consequently, it is possible to install the in-vehicle camera at low cost.

Here, an image obtained by photography by the in-vehicle camera may be sent to the cellular phone by wire using a cable or the like. Alternatively, the image may be sent to the cellular phone wirelessly by infrared communication or the like. Further, the operation of the cellular phone or the like and the operation of the car may be linked with each other. When a car is put into reverse gear, or a blinker is used, or the like, an image obtained by the in-vehicle camera may be automatically displayed on the display device of the cellular phone.

A display device for displaying the image obtained by the in-vehicle camera is not limited to the cellular phone. A mobile information terminal, such as PDA, a small-size personal computer, or a small-size car navigation that can be carried by a user may be used.

[Numerical Value Example of Imaging Lens]

Next, numerical value examples of imaging lenses of the present invention will be described. Lens cross sections of imaging lenses of Example 1 through Example 19 are illustrated in FIG. 3 through FIG. 21, respectively. In FIG. 3 through FIG. 21, the left side of the diagram is the object side, and the right side of the diagram is the image side. Further, aperture stop St, optical member PP and the imaging device 5, which is arranged on image plane Sim, are also illustrated in a similar manner to FIG. 1. In each diagram, aperture stop St does not represent the shape nor the size of aperture stop St but the position of aperture stop St on optical axis Z. In each example, signs Ri, Di (i=1, 2, 3, . . . ) in the lens cross section correspond to Ri, Di in lens data that will be described next.

The imaging lens according to the first embodiment of the present invention corresponds to Examples 1 through 15 and 17. The imaging lens according to the second embodiment of the present invention corresponds to Examples 1 through 15. The imaging lens according to the third embodiment of the present invention corresponds to Examples 1 through 19.

Table 1 through Table 19 show lens data about the imaging lenses of Example 1 through Example 19, respectively. In each table, (A) shows basic lens data, and (B) shows various kinds of data, and (C) shows aspherical surface data.

In the basic lens data, column Si shows the surface number of the i-th surface (i=1, 2, 3, . . . ). The object-side surface of the most object-side composition element is the first surface, and surface numbers sequentially increase toward the image side. Column Ri shows the curvature radius of the i-th surface, and column Di shows a distance between the i-th surface and the (i+1)th surface on optical axis Z. Here, the sign of a curvature radius is positive when the shape of a surface is convex toward the object side, and the sign of a curvature radius is negative when the shape of a surface is convex toward the image side. Further, column Ndj shows the refractive index of the j-th optical element (j=1, 2, 3, . . . ) for d-line (wavelength is 587.6 nm). The most object-side lens is the first optical element, and the number j sequentially increases toward the image side. The column vdj shows the Abbe number of the j-th optical element for d-line. Here, the basic lens data include aperture stop St and optical member PP. In the column of the surface number, the term (St) is also written for a surface corresponding to aperture stop St.

In the basic lens data, mark “*” is attached to the surface number of an aspherical surface. The basic lens data show, as the curvature radius of an aspherical surface, the numerical value of a paraxial curvature radius (a curvature radius at the center). The aspherical surface data show the surface numbers of aspherical surfaces and aspherical surface coefficients about the aspherical surfaces. In the aspherical surface data, “E−n” (n: integer) means “×10^(−n)”, and “E+n” means “×10^(n)”. Here, the aspherical surface coefficients are values of coefficients KA, RBm (m=3, 4, 5, . . . 20) in the following aspherical equation:

$\begin{matrix} {{{Zd} = {\frac{C \times Y^{2}}{1 + \sqrt{1 - {{KA} \times C^{2} \times Y^{2}}}} + {\sum\limits_{m}{R\; B_{m}Y^{m}}}}},} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack \end{matrix}$

Zd: depth of an aspherical surface (the length of a perpendicular from a point on the aspherical surface at height Y to a plane that contacts with the vertex of the aspherical surface and is perpendicular to the optical axis),

Y: height (the length from the optical axis to the lens surface),

C: paraxial curvature, and

KA, RBm: aspherical surface coefficients (m=3, 4, 5, . . . 20).

In various kinds of data, L is a distance (a back focus portion is a distance in air) on optical axis Z from the object-side surface of first lens L1 to image plane Sim, and Bf is a distance (corresponding to back focus, and distance in air) on optical axis Z from the image-side surface of the most image-side lens to image plane Sim. Further, f is the focal length of the entire system, and f1 is the focal length of first lens L1, and f2 is the focal length of second lens L2, and f3 is the focal length of third lens L3, and f4 is the focal length of fourth lens L4, and f5 is the focal length of fifth lens L5, and f6 is the focal length of sixth lens L6. Further, f56 is a combined focal length of fifth lens L5 and sixth lens L6, and f123 is a combined focal length of first lens L, second lens L2 and third lens L3, and ER1 is an effective radius of the object-side surface of first lens L1.

Tables 20 and 21 collectively show values corresponding to conditional formulas (1) through (21) for each example.

Here, conditional formula (1) is (D6+D7)/f. Conditional formula (2) is D12/f. Conditional formula (3) is f56/f. Conditional formula (4) is (R8+R9)/(R8−R9). Conditional formula (5) is R2/f. Conditional formula (6) is D3/f. Conditional formula (7) is (R12+R13)/(R12−R13). Conditional formula (8) is f5/f. Conditional formula (9) is D2/f. Conditional formula (10) is D5/f. Conditional formula (11) is L/f. Conditional formula (12) is Bf/f. Conditional formula (13) is vd3+vd5. Conditional formula (14) is (R3+R4)/(R3−R4). Conditional formula (15) is (R5+R6)/(R5−R6). Conditional formula (16) is (R1+R2)/(R1−R2). Conditional formula (17) is f123/f. Conditional formula (18) is f3/f. Conditional formula (19) is D9/f. Conditional formula (20) is f4/f. Conditional formula (21) is ER1/f, where

L: a length from the vertex of an object-side surface of first lens L1 to an image plane (a back focus portion is a distance in air),

Bf: a length from the vertex of an image-side surface of a most image-side lens to an image plane (a distance in air),

D2: an air space between first lens L1 and second lens L2 on an optical axis,

D3: the center thickness of second lens L2,

D5: the center thickness of third lens L3,

D6+D7: an air space between third lens L3 and fourth lens L4 on an optical axis,

D9: an air space between fourth lens L4 and fifth lens L5 on an optical axis,

D12: the center thickness of sixth lens L6

vd3: an Abbe number of the material of third lens L3 for d-line,

vd5: an Abbe number of the material of fifth lens L5 for d-line,

R1: a curvature radius of an object-side surface of first lens L1,

R2: a curvature radius of an image-side surface of first lens L1,

R3: a curvature radius of an object-side surface of second lens L2,

R4: a curvature radius of an image-side surface of second lens L2,

R5: a curvature radius of an object-side surface of third lens L3,

R6: a curvature radius of an image-side surface of third lens L3,

R8: a curvature radius of an object-side surface of fourth lens L4,

R9: a curvature radius of an image-side surface of fourth lens L4,

R12: a curvature radius of an object-side surface of sixth lens L6,

R13: a curvature radius of an image-side surface of sixth lens L6,

f: a focal length of an entire system,

f3: a focal length of third lens L3,

f4: a focal length of fourth lens L4,

f5: a focal length of fifth lens L5,

f56: a combined focal length of fifth lens L5 and sixth lens L6,

f123: a combined focal length of first lens L1, second lens L2 and third lens L3, and

ER1: an effective radius of an object-side surface of first lens.

As the unit of each numerical value, “mm” is used for length. However, this unit is only an example. Since an optical system can be used by proportionally enlarging or reducing the optical system, other appropriate units may be used.

TABLE 1 EXAMPLE 1 (A) Si Ri Di Ndj νdj  1 18.3300 1.10000 1.7725 49.6  2 4.2821 2.41086  *3 −10.9675 1.04000 1.5339 55.9  *4 2.0822 1.10385  *5 3.4282 2.70000 1.6336 23.6  *6 11.0506 0.34979  7(St) ∞ 0.30000  8 6.7259 2.65027 1.7550 52.3  9 −3.2121 0.20000  10 −4.3240 0.80000 1.9229 18.9  11 ∞ 0.15000 *12 5.7712 2.64633 1.5339 55.9 *13 −2.3745 2.00000  14 ∞ 0.55000 1.5168 64.2  15 ∞ 0.37877 IMAGE ∞ * PLANE (B) L 18.2 Bf 2.7 f 1.38 f1 −7.49 f2 −3.19 f3 6.90 f4 3.25 f5 −4.69 f6 3.55 f56 5.41 f123 −3.13 ER1 6.4 (C) SURFACE NUMBER KA RB3 RB4 RB5 RB6 3 0.0000000E+00  3.8300528E−02 −1.2203921E−03 −1.3342639E−03  −2.9306060E−04 4 0.0000000E+00  8.0386138E−02 −3.0984205E−02 2.3277895E−02  9.9713090E−03 5 0.0000000E+00 −3.3483114E−04  2.0468558E−02 2.5143483E−03  1.8796711E−03 6 0.0000000E+00 −1.5762733E−04  1.5962589E−02 1.2794484E−02 −1.9154762E−02 12 0.0000000E+00  3.2297689E−03 −7.4060853E−03 5.6984069E−04  4.9705503E−04 13 0.0000000E+00 −2.1658420E−03  1.4980160E−02 −1.6913242E−03  −7.7596670E−04 SURFACE NUMBER RB7 RB8 RB9 RB10 RB11 3 −3.0697136E−05  3.7714415E−06  3.0298547E−06  1.0247916E−06  2.3522192E−07 4 3.6442103E−04 −1.1873853E−03  −7.1877181E−04 −2.9007732E−04 −8.3911030E−05 5 5.4332978E−04 −3.4104862E−04  −2.7491475E−04 −4.3236723E−05  4.4585419E−05 6 1.2411890E−02 2.0822314E−02 −4.7699952E−04 −1.9440064E−02 −1.7745559E−02 12 1.0922267E−04 1.0909132E−05 −9.6273651E−07 −8.0044142E−07 −3.9501979E−07 13 1.4460435E−05 9.3129201E−05  3.4470693E−05  6.3519131E−06 −1.5002912E−06 SURFACE NUMBER RB12 RB13 RB14 RB15 RB16 3  3.0377619E−08 −5.3078151E−09 −4.5298394E−09 −1.6702149E−09 −3.7083760E−10 4 −1.1054129E−05  6.4658723E−06  6.4987795E−06  3.3257377E−06  1.1299315E−06 5  3.1191005E−05  8.5866426E−06 −1.6627707E−06 −3.2222937E−06 −1.9037596E−06 6  1.3102408E−02 −1.8435194E−02  8.3527067E−02 −7.3097711E−02 −3.3379937E−02 12 −2.2230840E−07 −1.5412219E−07 −6.7353491E−08 −1.5631228E−08  4.3939708E−09 13 −1.4117923E−06 −4.9131247E−07 −3.5293605E−08  7.6053938E−08  8.3618963E−08 SURFACE NUMBER RB17 RB18 RB19 RB20 3 −2.0657146E−11 3.8213084E−11  8.1555895E−12 −1.1452319E−12 4  1.2187485E−07 −1.3545855E−07  −9.6552895E−08  1.7808281E−08 5 −4.5910144E−07 1.5048991E−07  2.1783866E−07 −3.9255842E−08 6  1.2155611E−01 −1.1001173E−01   4.0730415E−02 −4.0146188E−03 12  8.1232698E−09 3.9200026E−09 −5.3565231E−10 −4.8031671E−10 13 −2.2757698E−08 9.8934239E−09 −5.8430684E−09  9.1165409E−10

TABLE 2 EXAMPLE 2 (A) Si Ri Di Ndj νdj  1 18.9561 1.10000 1.7725 49.6  2 4.3867 2.28987  *3 −12.3083 1.04000 1.5339 55.9  *4 1.9729 1.16578  *5 3.3130 2.70000 1.6336 23.6  *6 10.4808 0.30827  7(St) ∞ 0.30000  8 6.5165 2.65028 1.7550 52.3  9 −3.1039 0.20000  10 −4.1171 0.80000 1.9229 18.9  11 ∞ 0.15000 *12 5.9265 2.13612 1.5339 55.9 *13 −2.3234 2.00000  14 ∞ 0.55000 1.5168 64.2  15 ∞ 0.37984 IMAGE ∞ * PLANE (B) L 17.6 Bf 2.7 f 1.35 f1 −7.64 f2 −3.11 f3 6.67 f4 3.16 f5 −4.46 f6 3.44 f56 5.70 f123 −3.20 ER1 6.4 (C) SURFACE NUMBER KA RB3 RB4 RB5 RB6 3 0.0000000E+00  4.0338046E−02 −1.0743021E−03 −1.3340914E−03  −3.0300139E−04 4 0.0000000E+00  8.2006053E−02 −3.0966821E−02 2.2600377E−02  9.7052044E−03 5 0.0000000E+00 −4.1031457E−04  1.8655539E−02 2.3662765E−03  1.8452264E−03 6 0.0000000E+00 −8.4164986E−04  1.9303764E−02 8.3087206E−03 −1.5159560E−02 12 0.0000000E+00  2.7056963E−03 −8.3331435E−03 3.5915384E−04  4.9037990E−04 13 0.0000000E+00 −3.7165884E−03  1.4720134E−02 −1.6720482E−03  −7.6194511E−04 SURFACE NUMBER RB7 RB8 RB9 RB10 RB11 3 −3.5147716E−06  2.3942538E−06  2.6923338E−06  9.6321333E−07  2.3044629E−07 4 2.8607614E−04 −1.2051468E−03  −7.2016083E−04 −2.8843184E−04 −8.2443878E−05 5 5.6034979E−04 −3.0563804E−04  −2.5133363E−04 −3.4860208E−05  4.4771475E−05 6 1.4903042E−02 1.8619237E−02 −4.0107532E−03 −2.1523904E−02 −1.6916637E−02 12 1.2396396E−04 1.8357634E−05  1.3536371E−06 −2.9365113E−07 −3.3725780E−07 13 8.0443566E−06 9.0020119E−05  3.3078743E−05  6.2839651E−06 −1.3033089E−06 SURFACE NUMBER RB12 RB13 RB14 RB15 RB16 3  3.3222817E−08 −3.7445771E−09 −3.9352154E−09 −1.4883284E−09 −3.2778828E−10 4 −1.0291323E−05  6.7878911E−06  6.6186647E−06  3.3789865E−06  1.1545893E−06 5  2.9191842E−05  6.9740336E−06 −2.4342311E−06 −3.4355531E−06 −1.3795784E−06 6  1.5220420E−02 −1.5867659E−02  8.5456845E−02 −7.3423461E−02 −3.4403288E−02 12 −2.3199793E−07 −1.5993614E−07 −6.7321062E−09 −1.4274329E−08  5.2956273E−09 13 −1.2571666E−06 −4.1616396E−07 −4.9188042E−09  8.8011678E−08  6.6092828E−08 SURFACE NUMBER RB17 RB18 RB19 RB20 3 −1.7169096E−11 3.4964233E−11  6.7873782E−12 −1.2105185E−12 4  1.3587984E−07 −1.3175931E−07  −9.9572847E−08  1.4561404E−08 5 −3.9305727E−07 1.9372832E−07  2.3498032E−07 −4.5838906E−08 6  1.2048389E−01 −1.1096351E−01   4.0239417E−02 −3.1771880E−03 12  8.3771209E−09 3.9001134E−09 −5.1492254E−10 −6.0722910E−10 13 −2.3077283E−08 9.4788573E−09 −6.0470120E−09  7.9923495E−10

TABLE 3 EXAMPLE 3 (A) Si Ri Di Ndj νdj  1 19.3524 1.10000 1.7725 49.6  2 4.4984 2.35679  *3 −11.3495 1.04000 1.5339 55.9  *4 2.1197 1.08210  *5 3.4613 2.70000 1.6336 23.6  *6 9.5676 0.40060  7(St) ∞ 0.30000  8 6.9466 2.65027 1.7550 52.3  9 −3.2558 0.20000  10 −4.6898 0.80000 1.9229 18.9  11 ∞ 0.15000 *12 6.2734 2.70945 1.5339 55.9 *13 −2.2213 2.00000  14 ∞ 0.70066 1.5168 64.2  15 ∞ 0.20776 IMAGE ∞ * PLANE (B) L 18.2 Bf 2.7 f 1.35 f1 −7.84 f2 −3.26 f3 7.31 f4 3.31 f5 −5.08 f6 3.46 f56 4.80 f123 −3.05 ER1 6.3 (C) SURFACE NUMBER KA RB3 RB4 RB5 RB6 3 0.0000000E+00  3.7551531E−02 −1.2892048E−03 −1.3302647E−03  −2.9256774E−04 4 0.0000000E+00  8.0359552E−02 −3.2121460E−02 2.2191449E−02  9.5559299E−03 5 0.0000000E+00 −7.3639082E−04  2.1768367E−02 2.0504466E−03  1.4961870E−03 6 0.0000000E+00 −1.2031605E−03  2.0753176E−02 1.1235278E−02 −2.1121387E−02 12 0.0000000E+00  2.5501041E−03 −8.1338797E−03 3.6277463E−04  4.1568374E−04 13 0.0000000E+00 −6.7882388E−04  1.4529059E−02 −1.9449092E−03  −8.2324579E−04 SURFACE NUMBER RB7 RB8 RB9 RB10 RB11 3 −2.9022210E−05   4.2228128E−06  3.1139496E−08  1.0294459E−06  2.3052006E−07 4 2.7167009E−04 −1.1884789E−03 −7.0610793E−04 −2.8067345E−04 −7.6680267E−05 5 4.8446076E−04 −2.9568921E−04 −2.4016807E−04 −3.3391941E−05  4.2491904E−05 6 1.1722830E−02  2.1126024E−02  2.3204559E−04 −1.8841767E−02 −1.7530390E−02 12 7.2781037E−05 −3.2532707E−06 −5.0506636E−06 −1.3565631E−06 −1.4015390E−07 13 7.7504874E−06  8.9265676E−05  3.1465481E−05  4.6781939E−06 −2.2174023E−06 SURFACE NUMBER RB12 RB13 RB14 RB15 RB16 3 2.7683302E−08 −5.2173746E−09 −4.7459452E−09 −1.6959921E−09 −3.6295172E−10 4 −8.4422100E−08   7.6874514E−06  7.0298694E−06  3.5287852E−06  1.1899077E−06 5 2.7082304E−05  5.9213419E−06 −2.7338979E−06 −3.4002279E−05 −1.7665238E−06 6 1.2960253E−02 −1.8593865E−02  8.3206254E−02 −7.3381240E−02 −3.3162449E−02 12 2.7436323E−08 −3.0662470E−08 −2.6139702E−08 −8.3148057E−09  2.4139814E−09 13 −1.6568921E−06  −5.5400788E−07 −4.2760435E−08  6.2048172E−08  6.7894662E−08 SURFACE NUMBER RB17 RB18 RB19 RB20 3 −1.4528507E−11 4.0903279E−11  8.7476565E−12 −1.3621097E−12 4  1.2808857E−07 −1.4480953E−07  −1.0667854E−07  1.0583634E−08 5 −3.0196240E−07 2.4621297E−07  2.4299686E−07 −5.9144405E−08 6  1.2103157E−01 −1.0995504E−01   4.0789070E−02 −3.7440283E−03 12  5.6444952E−09 2.6279788E−09 −1.0468448E−09 −2.8130423E−10 13 −2.1302783E−08 1.0544992E−08 −5.8603043E−09  8.1807959E−10

TABLE 4 EXAMPLE 4 (A) Si Ri Di Ndj νdj  1 20.0756 1.10000 1.7725 49.6  2 4.3584 2.30398  *3 −15.6992 1.04000 1.5339 55.9  *4 2.0060 1.08063  *5 3.2644 2.70000 1.6336 23.6  *6 8.4153 0.40316  7(St) ∞ 0.30000  8 7.1573 2.65027 1.7550 52.3  9 −3.1856 0.20000  10 −4.6223 0.80000 1.9229 18.9  11 ∞ 0.15000 *12 5.9317 2.77086 1.5339 55.9 *13 −2.2494 2.00000  14 ∞ 0.40000 1.5168 64.2  15 ∞ 0.40576 IMAGE ∞ * PLANE (B) L 18.2 Bf 2.7 f 1.34 f1 −7.43 f2 −3.26 f3 7.00 f4 3.28 f5 −5.01 f6 3.46 f56 4.82 f123 −2.98 ER1 6.3 (C) SURFACE NUMBER KA RB3 RB4 RB5 RB6 3 0.0000000E+00  3.6895301E−02 −1.4449016E−03 −1.3354851E−03  −2.8518700E−04 4 0.0000000E+00  7.7675871E−02 −2.9136598E−02 2.1938476E−02  9.1478855E−03 5 0.0000000E+00 −2.0367848E−03  2.3021351E−02 2.1014123E−03  1.2219900E−03 6 0.0000000E+00 −7.8793970E−04  1.9435050E−02 1.4064488E−02 −2.1148269E−02 12 0.0000000E+00  2.9221550E−03 −8.5080988E−03 4.7569663E−04  4.5410782E−04 13 0.0000000E+00 −5.8373348E−04  1.4832616E−02 −2.1607847E−03  −8.6217115E−04 SURFACE NUMBER RB7 RB8 RB9 RB10 RB11 3 −2.7726578E−05   4.5133875E−06  3.1374421E−06  1.0154350E−06  2.2036498E−07 4 1.1811636E−04 −1.2177217E−03 −7.0163676E−04 −2.7283138E−04 −7.3690478E−05 5 4.0294010E−04 −2.7115641E−04 −2.0895292E−04 −1.9954111E−05  4.4404918E−05 6 1.0446959E−02  2.0710501E−02  7.9811269E−04 −1.8020980E−02 −1.6895939E−02 12 6.7070206E−05 −1.2792171E−05 −9.7787320E−06 −2.7853207E−06 −3.2192727E−07 13 1.5584293E−05  9.4896238E−05  3.2885312E−05  4.5101540E−06 −2.4898690E−06 SURFACE NUMBER RB12 RB13 RB14 RB15 RB16 3 2.4393833E−08 −7.3179872E−09 −4.9529704E−09 −1.7019372E−09 −3.4229484E−10 4 −5.9831300E−06   8.6992637E−06  7.3623911E−06  3.5841558E−06  1.1625686E−06 5 2.5485990E−05  4.4349811E−06 −3.3902900E−06 −3.4987623E−06 −1.6586718E−06 6 1.3201353E−02 −1.8230690E−02  8.2673021E−02 −7.3621193E−02 −3.2762814E−02 12 1.2133844E−07  5.2184545E−08  1.0114388E−08  1.1623336E−09  2.4277120E−09 13 −1.8000828E−06  −6.0584710E−07 −5.5874525E−08  8.0922210E−08  6.9046519E−08 SURFACE NUMBER RB17 RB18 RB19 RB20 3 −1.3956764E−12 4.6113029E−11  9.3019279E−12 −1.9893847E−12 4  9.1745066E−08 −1.6653950E−07  −1.1109243E−07  1.2617392E−08 5 −1.7041461E−07 3.1774786E−07  2.5542954E−07 −7.9827270E−08 6  1.2032052E−01 −1.1043471E−01   4.0509447E−02 −2.7771419E−03 12  4.0896230E−09 1.6525616E−09 −1.4312864E−09 −9.7207514E−11 13 −2.0734752E−08 1.0937383E−08 −5.8611431E−09  7.9706782E−10

TABLE 5 EXAMPLE 5 (A) Si Ri Di Ndj νdj  1 18.2309 1.10000 1.7725 49.6  2 4.2655 2.36488  *3 −14.3608 1.04000 1.5339 55.9  *4 1.8967 1.14456  *5 3.3658 2.70000 1.6336 23.6  *6 9.4707 0.35592  7(St) ∞ 0.30000  8 6.5456 2.65000 1.7550 52.3  9 −3.1926 0.20000  10 −4.3364 0.80000 1.9229 18.9  11 ∞ 0.15000 *12 5.6339 2.55868 1.5339 55.9 *13 −2.3389 2.00000  14 ∞ 0.30000 1.5168 64.2  15 ∞ 0.54266 IMAGE ∞ * PLANE (B) L 18.1 Bf 2.7 f 1.32 f1 −7.46 f2 −3.07 f3 7.03 f4 3.22 f5 −4.70 f6 3.48 f56 5.27 f123 −2.87 ER1 6.5 (C) SURFACE NUMBER KA RB3 RB4 RB5 RB6 3 0.0000000E+00  3.7811555E−02 −1.6160127E−03 −1.4095377E−03  −3.0221910E−04 4 0.0000000E+00  7.4931771E−02 −3.1633167E−02 2.3119481E−02  1.0008256E−02 5 0.0000000E+00 −5.1131479E−03  2.2074704E−02 3.0719775E−03  1.8526233E−03 6 0.0000000E+00 −8.9411174E−04  1.9405032E−02 1.0981925E−02 −1.7212328E−02 12 0.0000000E+00  4.3154744E−03 −7.0669105E−03 6.1739432E−04  4.9263058E−04 13 0.0000000E+00 −1.4811408E−05  1.5681532E−02 −1.7239449E−03  −7.9108696E−04 SURFACE NUMBER RB7 RB8 RB9 RB10 RB11 3 −3.0735246E−05  4.1828658E−06  3.2034393E−06  1.0786706E−06  2.4985090E−07 4 4.0057849E−04 −1.1753560E−03  −7.1891984E−04 −2.9310423E−04 −8.6296934E−05 5 4.5609354E−04 −3.6753804E−04  −2.7270189E−04 −3.6915445E−05  4.7574047E−05 6 1.3724146E−02 1.9615554E−02 −2.3819658E−03 −2.0798381E−02 −1.7378631E−02 12 1.0668437E−04 1.1207469E−05 −2.9527996E−07 −4.1980210E−07 −2.5621751E−07 13 1.1866220E−05 9.5240445E−05  3.5185620E−05  6.7433629E−06 −1.3068711E−06 SURFACE NUMBER RB12 RB13 RB14 RB15 RB16 3  3.3807961E−08 −4.7299349E−09 −4.4936930E−09 −1.7003329E−09 −3.8849878E−10 4 −1.2451591E−06  5.8162544E−06  6.2407990E−06  3.2559166E−06  1.1256385E−06 5  3.1912358E−05  8.4495446E−06 −2.0043911E−06 −3.4761417E−06 −2.0322497E−06 6  1.4245183E−02 −1.7196294E−02  8.4967937E−03 −7.2935404E−02 −3.3625789E−02 12 −1.9072134E−07 −1.5462652E−07 −7.2535581E−08 −1.9075035E−08  2.8798823E−09 13 −1.3247424E−06 −4.6145349E−07 −2.6256064E−09  8.0100644E−08  6.3718843E−08 SURFACE NUMBER RB17 RB18 RB19 RB20 3 −2.6709783E−11 3.4972980E−11  7.1825777E−12 −6.1501468E−13 4  1.3622319E−07 −1.2526405E−07  −9.4629348E−08  2.1467086E−08 5 −4.9246045E−07 1.4161194E−07  2.2618228E−07 −2.8477257E−08 6  1.2012240E−01 −1.1045902E−01   4.0359007E−02 −3.4225506E−03 12  7.5834395E−09 3.8142324E−09 −4.2353527E−10 −4.5096091E−10 13 −2.2748883E−08 9.5194244E−09 −5.9252070E−09  8.8948423E−10

TABLE 6 EXAMPLE 6 (A) Si Ri Di Ndj νdj  1 19.2029 1.10000 1.7725 49.6  2 4.3241 2.34599  *3 −12.2457 1.04002 1.5339 55.9  *4 2.0566 1.12244  *5 3.3991 2.70000 1.6336 23.6  *6 9.7780 0.33999  7(St) ∞ 0.30000  8 6.5829 2.65027 1.7550 52.3  9 −3.1673 0.20000  10 −4.2361 0.80000 1.9229 18.9  11 ######## 0.15000 *12 5.8977 2.56093 1.5339 55.9 *13 −2.3846 0.15000  14 ∞ 0.80000 1.5168 64.2  15 ∞ 2.06399 IMAGE ∞ * PLANE (B) L 18.1 Bf 2.7 f 1.38 f1 −7.46 f2 −3.22 f3 7.06 f4 3.21 f5 −4.74 f6 3.56 f56 5.47 f123 −3.04 ER1 6.4 (C) SURFACE NUMBER KA RB3 RB4 RB5 RB6 3 0.0000000E+00  3.8645011E−02 −1.2858181E−03 −1.3510637E−03  −2.9799189E−04 4 0.0000000E+00  8.1064040E−02 −3.0513124E−02 2.3221307E−02  9.9056824E−03 5 0.0000000E+00 −1.0721532E−03  2.1168606E−02 2.5241749E−03  1.7251796E−03 6 0.0000000E+00 −9.7495149E−04  1.8576393E−02 9.5516233E−03 −1.6350427E−02 12 0.0000000E+00  3.4146319E−03 −7.3970021E−03 5.6231525E−04  5.0274368E−04 13 0.0000000E+00 −2.1742389E−03  1.4926714E−02 −1.8486916E−03  −7.5499826E−04 SURFACE NUMBER RB7 RB8 RB9 RB10 RB11 3 −3.2131985E−05  3.3935383E−06  2.9507687E−06  1.0163721E−06  2.3766645E−07 4 3.2520801E−04 −1.2063294E−03  −7.2699830E−04 −2.9341121E−04 −8.5112640E−05 5 4.8429462E−04 −3.3517903E−04  −2.5800421E−04 −3.3630081E−05  4.7264250E−05 6 1.4724096E−02 1.9716312E−02 −2.8359381E−03 −2.1279406E−02 −1.7692037E−02 12 1.1476957E−04 1.3434775E−05 −1.9075347E−07 −6.4993752E−07 −4.0098856E−07 13 1.5327209E−05 9.3616852E−05  3.4076604E−05  6.3393832E−06 −1.4307159E−06 SURFACE NUMBER RB12 RB13 RB14 RB15 RB16 3  3.2389149E−08 −4.5631269E−09 −4.3079394E−09 −1.6125328E−09 −3.6343267E−10 4 −1.1508615E−05  6.3047281E−06  6.4438894E−06  3.3224363E−06  1.1394024E−06 5  3.0859020E−05  7.6957433E−06 −2.2927330E−06 −3.5164732E−06 −1.9917344E−06 6  1.4160312E−02 −1.7059710E−02  8.4959433E−02 −7.2627908E−02 −3.4173364E−02 12 −2.4459224E−07 −1.6685416E−07 −7.2198692E−08 −1.6972053E−08  4.1837939E−09 13 −1.3550861E−06 −4.669581E−07  −2.5510888E−08  8.0869494E−08  6.4157036E−08 SURFACE NUMBER RB17 RB18 RB19 RB20 3 −2.1692362E−11 3.6112090E−11  7.1750163E−12 −1.0393877E−12 4  1.3355717E−07 −1.2912403E−07  −9.5982359E−08  1.8510987E−08 5 −4.6002655E−07 1.6344464E−07  2.3067954E−07 −3.4515674E−08 6  1.2121900E−01 −1.1048706E−01   4.0307671E−02 −3.6939612E−03 12  8.0994340E−09 3.9302517E−09 −4.3646224E−10 −5.1231052E−10 13 −2.2828942E−08 9.8004363E−09 −5.8949897E−09  8.9301272E−10

TABLE 7 EXAMPLE 7 (A) Si Ri Di Ndj νdj  1 19.0143 1.10000 1.7725 49.6  2 4.2822 2.41665  *3 −11.9650 1.04439 1.5110 55.2  *4 1.9510 1.12727  *5 3.3580 2.70000 1.6140 25.5  *6 11.6317 0.34490  7(St) ∞ 0.30000  8 6.4440 2.65027 1.7130 53.9  9 −3.0978 0.20000  10 −4.2395 0.80000 1.9229 18.9  11 ######## 0.15000 *12 5.4289 2.64099 1.5110 55.2 *13 −2.2367 2.00000  14 ∞ 0.55000 1.5168 64.2  15 ∞ 0.37857 IMAGE ∞ PLANE (B) L 18.2 Bf 2.7 f 1.36 f1 −7.40 f2 −3.20 f3 6.84 f4 3.32 f5 −4.68 f6 3.51 f56 5.22 f123 −3.19 ER1 6.4 (C) SURFACE NUMBER KA RB3 RB4 RB5 RB6 3 0.0000000E+00  3.7195457E−02 −1.5029063E−03 −1.3680469E−03  −2.9408784E−04 4 0.0000000E+00  7.8142180E−02 −2.9256774E−02 2.3754836E−02  1.0000802E−02 5 0.0000000E+00 −4.0815105E−04  2.1581699E−02 2.8751661E−03  1.8802502E−03 6 0.0000000E+00 −7.1139628E−04  1.8384332E−02 1.0241171E−02 −1.7384277E−02 12 0.0000000E+00  1.7567774E−03 −7.5528037E−03 6.0648445E−04  5.1898713E−04 13 0.0000000E+00 −1.7154267E−03  1.5317294E−02 −1.6985412E−03  −7.8763392E−04 SURFACE NUMBER RB7 RB8 RB9 RB10 RB11 3 −2.9719912E−05  4.1796430E−06  3.1479403E−03  1.0535937E−06  2.4133789E−07 4 3.1220623E−04 −1.2294244E−03  −7.4210620E−04 −3.0115418E−04 −8.8572737E−05 5 5.2129366E−04 −3.3746159E−04  −2.6506137E−04 −3.7313843E−05  4.6351276E−05 6 1.4407392E−02 2.0611580E−02 −1.7179144E−03 −2.0699573E−02 −1.7735108E−02 12 1.1614524E−04 1.2347537E−05 −9.2213678E−07 −9.4091586E−07 −4.8639161E−07 13 9.4389606E−06 9.3915509E−05  3.4635185E−05  6.5360493E−06 −1.4029521E−06 SURFACE NUMBER RB12 RB13 RB14 RB15 RB16 3  3.1372173E−08 −6.3341720E−09 −4.6158450E−09 −1.7130976E−09 −3.8707383E−10 4 −1.2876140E−05  5.8354423E−08  6.3126873E−06  3.3011785E−06  1.1461831E−08 5  3.1042462E−05  8.0362632E−06 −2.0668868E−08 −3.4220461E−08 −1.9717796E−06 6  1.3632522E−02 −1.7401161E−02  8.4562120E−02 −7.3205382E−02 −3.4113991E−02 12 −2.6047584E−07 −1.6543327E−07 −6.8866085E−08 −1.4848122E−08  5.1674133E−09 13 −1.3571016E−06 −4.7844789E−07 −3.1731155E−08  7.6384095E−08  6.3366707E−08 SURFACE NUMBER RB17 RB18 RB19 RB20 3 −2.5817627E−11 3.5706564E−11  7.7310689E−12 −8.1390839E−13 4  1.4314766E−07 −1.2169080E−07  −9.0240437E−09  2.1250539E−09 5 −4.5525611E−07 1.5400817E−07  2.2321702E−07 −3.7647472E−08 6  1.2160303E−01 −1.1033290E−01   4.0466775E−02 −3.6757261E−03 12  8.4524590E−09 4.0231896E−09 −4.4129856E−10 −5.4184985E−10 13 −2.2909732E−08 9.6166208E−09 −5.8385090E−09  9.1882156E−10

TABLE 8 EXAMPLE 8 (A) Si Ri Di Ndj νdj  1 18.6165 1.10000 1.7725 49.6  2 4.3350 2.40281  *3 −11.6217 1.04439 1.5316 55.1  *4 2.0105 1.12841  *5 3.4002 2.70000 1.6140 25.5  *6 12.6334 0.34626  7(St) ∞ 0.30000  8 6.2806 2.65027 1.6935 53.2  9 −3.0691 0.20000  10 −4.3064 0.80000 1.9229 18.9  11 176.8730 0.15000 *12 5.3872 2.64198 1.5316 55.1 *13 −2.3075 2.00000  14 ∞ 0.40000 1.5168 64.2  15 ∞ 0.519674z IMAGE ∞ PLANE (B) L 18.2 Bf 2.8 f 1.36 f1 −7.57 f2 −3.14 f3 6.82 f4 3.36 f5 −4.55 f6 3.45 f56 5.19 f123 −3.22 ER1 6.4 (C) SURFACE NUMBER KA RB3 RB4 RB5 RB6 3 0.0000000E+00 3.7031111E−02 −1.4861272E−03 −1.3560185E−03  −2.9011136E−04 4 0.0000000E+00 7.8448468E−02 −2.9278760E−02 2.3649000E−02  9.9199619E−03 5 0.0000000E+00 2.3280998E−04  2.1984603E−02 2.9015955E−03  1.8431919E−03 6 0.0000000E+00 −5.2097728E−04   1.7918477E−02 1.0796810E−02 −1.6945857E−02 12 0.0000000E+00 2.3095486E−03 −7.5584884E−03 5.8022420E−04  5.0979171E−04 13 0.0000000E+00 −2.4823911E−03   1.5173109E−02 −1.7259590E−03  −7.9301496E−04 SURFACE NUMBER RB7 RB8 RB9 RB10 RB11 3 −2.8710092E−05  4.3634779E−06  3.1745098E−06  1.0615327E−06  2.3823933E−07 4 2.7058858E−04 −1.2466776E−03  −7.4786239E−04 −3.0236650E−04 −8.8341253E−05 5 4.9400076E−04 −3.4990523E−04  −2.6978555E−04 −3.7579211E−05  4.6953470E−05 6 1.4549219E−02 2.0580418E−02 −1.6586591E−03 −2.0859746E−02 −1.7854642E−02 12 1.1351559E−04 1.1939126E−05 −8.9233239E−07 −8.9035890E−07 −4.6554419E−07 13 8.6701313E−06 9.3965857E−05  3.4624699E−05  6.5160932E−06 −1.4196877E−06 SURFACE NUMBER RB12 RB13 RB14 RB15 RB16 3  2.9913863E−08 −5.9648799E−09 −4.7758941E−09 −1.7546707E−09 −3.9637625E−10 4 −1.2380826E−05  6.2335752E−06  6.5617557E−06  3.4337729E−06  1.2053981E−06 5  3.1576079E−05  8.3241877E−06 −1.9815614E−06 −3.4075290E−06 −1.9874320E−06 6  1.3540241E−02 −1.7391205E−02  8.4603686E−02 −7.3140580E−02 −3.4009526E−02 12 −2.5825374E−07 −1.6627289E−07 −7.0225208E−08 −1.5678850E−08  4.8039852E−09 13 −1.3768332E−06 −4.8303174E−07 −3.3615852E−08  7.7699772E−08  6.3253749E−08 SURFACE NUMBER RB17 RB18 RB19 RB20 3 −2.6756950E−11 3.6379286E−11  8.3203681E−12 −7.0525857E−13 4  1.6523750E−07 −1.1767163E−07  −9.3527664E−08  1.6096763E−08 5 −4.7863666E−07 1.4462068E−07  2.2098831E−07 −3.5237048E−08 6  1.2171736E−01 −1.1033733E−01   4.0418184E−02 −3.7982289E−03 12  8.3379833E−09 4.0062008E−09 −4.3367894E−10 −5.2634625E−10 13 −2.2957596E−08 9.6126126E−09 −5.8352927E−09  9.2242241E−10

TABLE 9 EXAMPLE 9 (A) Si Ri Di Ndj νdj  1 17.9020 1.10000 1.8348 42.7  2 4.4051 2.28419  *3 −12.6079 1.04000 1.5339 55.9  *4 1.9862 1.16000  *5 3.0722 2.70000 1.5836 30.3  *6 11.8857 0.37412  7(St) ∞ 0.30000  8 6.5423 2.65028 1.7550 52.3  9 −3.0399 0.20000  10 −3.7244 0.80000 1.9229 18.9  11 ∞ 0.15000 *12 6.0446 2.18621 1.5339 55.9 *13 −2.2636 0.15000  14 ∞ 0.30000 1.5168 64.2  15 ∞ 2.46120 IMAGE ∞ PLANE (B) L 17.8 Bf 2.8 f 1.35 f1 −7.27 f2 −3.11 f3 6.38 f4 3.12 f5 −4.04 f6 3.40 f56 5.84 f123 −3.36 ER1 6.3 (C) SURFACE NUMBER KA RB3 RB4 RB5 RB6 3 0.0000000E+00 4.0069111E−02 −1.0909752E−03 −1.3279741E−03  −2.9995516E−04 4 0.0000000E+00 8.2560885E−02 −3.0360645E−02 2.2741841E−02  9.6717044E−03 5 0.0000000E+00 8.7456590E−04  2.0155204E−02 2.3253300E−03  1.9642746E−03 6 0.0000000E+00 −1.0692445E−03   2.0303446E−02 8.5300591E−03 −1.5532655E−02 12 0.0000000E+00 3.7095217E−03 −8.0479542E−03 4.0113299E−04  4.8901267E−04 13 0.0000000E+00 −3.1701632E−03   1.4949781E−02 −1.6526096E−03  −7.6448035E−04 SURFACE NUMBER RB7 RB8 RB9 RB10 RB11 3 −3.4295467E−05  2.5779545E−06  2.7220272E−06  9.6435612E−07  2.2888744E−07 4 2.4785786E−04 −1.2229525E−03  −7.2553014E−04 −2.8896308E−04 −8.1722105E−05 5 5.7665814E−04 −3.1160910E−04  −2.5693580E−04 −3.6940471E−05  4.4741640E−05 6 1.5380491E−02 1.9831757E−02 −2.8620761E−03 −2.0873767E−02 −1.6924730E−02 12 1.2037604E−04 1.6800157E−05  8.7837836E−07 −4.1257802E−07 −3.6487590E−07 13 7.7806763E−06 9.0411191E−05  3.3260105E−05  6.2991049E−06 −1.3334462E−06 SURFACE NUMBER RB12 RB13 RB14 RB15 RB16 3  3.2384867E−08 −4.0320178E−09 −4.0453984E−09 −1.5185435E−09 −3.3545315E−10 4 −9.5466925E−06  7.2819510E−06  6.3890820E−06  3.5068963E−06  1.2056015E−06 5  2.9790932E−05  7.5334511E−06 −2.0806878E−06 −3.2571365E−06 −1.8064487E−06 6  1.4827030E−02 −1.6216016E−02  8.4843674E−02 −7.3921216E−02 −3.4462017E−02 12 −2.3990376E−07 −1.6338990E−07 −6.9089596E−08 −1.5089532E−08  4.9984567E−09 13 −1.2835506E−06 −4.3091334E−07 −1.1541086E−08  8.5485572E−08  6.5289266E−06 SURFACE NUMBER RB17 RB18 RB19 RB20 3 −1.9409567E−11 3.5294468E−11  6.9043377E−12 −1.1648345E−12 4  1.5040624E−07 −1.3207801E−07  −1.0394735E−07  9.4001663E−09 5 −3.7060931E−07 1.9736093E−07  2.3130887E−07 −4.9879361E−08 6  1.2026944E−01 −1.1095025E−01   4.0575315E−02 −2.5535099E−03 12  8.3139381E−09 3.9165007E−09 −4.8590675E−10 −5.8108764E−10 13 −2.3251194E−08 9.4758948E−09 −6.0155654E−09  8.2494490E−10

TABLE 10 EXAMPLE 10 (A) Si Ri Di Ndj νdj  1 19.5803 1.10000 1.7550 52.3  2 4.2212 2.29380  *3 −12.4510 1.04000 1.5339 55.9  *4 1.9709 1.13366  *5 3.1309 2.55984 1.6140 25.5  *6 11.2086 0.36032  7(St) ∞ 0.30000  8 6.6118 2.65028 1.7725 49.6  9 −3.0702 0.20000  10 −3.7319 0.80000 1.9229 18.9  11 ∞ 0.15000 *12 5.9238 2.18027 1.5339 55.9 *13 −2.2424 0.15000  14 ∞ 0.60000 1.5168 64.2  15 ∞ 2.19550 IMAGE ∞ PLANE (B) L 17.5 Bf 2.7 f 1.36 f1 −7.35 f2 −3.11 f3 6.31 f4 3.08 f5 −4.04 f6 3.36 f56 5.69 f123 −3.36 ER1 6.4 (C) SURFACE NUMBER KA RB3 RB4 RB5 RB6 3 0.0000000E+00 3.9948848E−02 −1.1137545E−03 −1.3309814E−03  −3.0038892E−04 4 0.0000000E+00 8.1784930E−02 −3.0331822E−02 2.2741218E−02  9.6428532E−03 5 0.0000000E+00 7.7132831E−04  1.9878510E−02 2.6597867E−03  1.9123889E−03 6 0.0000000E+00 −7.9245340E−04   1.9903167E−02 6.1410514E−03 −1.5761885E−02 12 0.0000000E+00 3.0766875E−03 −8.1211176E−03 3.9751876E−04  4.9032983E−04 13 0.0000000E+00 −3.1515149E−03   1.5067387E−02 −1.6268569E−03  −7.6255645E−04 SURFACE NUMBER RB7 RB8 RB9 RB10 RB11 3 −3.4402300E−05  2.5420387E−06  2.7105504E−06  9.6119859E−07  2.2817587E−07 4 2.2291919E−04 −1.2383655E−03  −7.3389469E−04 −2.9319958E−04 −8.3764309E−05 5 5.7289704E−04 −3.0423713E−04  −2.5078518E−04 −3.3824921E−05  4.5824150E−05 6 1.5345355E−02 1.9908451E−02 −2.7725467E−03 −2.0931303E−02 −1.6938937E−02 12 1.2104778E−04 1.7059500E−05  9.8949984E−07 −3.5960001E−07 −3.3942046E−07 13 6.9465913E−06 8.9932412E−05  3.3112590E−05  6.2735765E−06 −1.3294587E−06 SURFACE NUMBER RB12 RB13 RB14 RB15 RB16 3  3.2265177E−08 −4.0826797E−09 −4.0363851E−09 −1.5135919E−09 −3.3362723E−10 4 −1.0485898E−05  6.8736940E−06  6.7251867E−06  3.4494035E−06  1.1912463E−06 5  2.9933653E−05  7.3725445E−06 −2.2717191E−06 −3.3959598E−06 −1.8878295E−06 6  1.4767616E−02 −1.6299221E−02  8.4765081E−02 −7.3983858E−02 −3.4508226E−02 12 −2.2830939E−07 −1.5848224E−07 −6.7176761E−08 −1.4405761E−08  5.2181870E−09 13 −1.2770921E−08 −4.2691728E−07 −9.6230802E−09  8.6283748E−08  6.5583930E−08 SURFACE NUMBER RB17 RB18 RB19 RB20 3 −1.7843927E−11 3.5471944E−11  6.9344125E−12 −1.1680562E−12 4  1.5144090E−07 −1.2696575E−07  −9.8807547E−08  1.3386159E−08 5 −4.1076326E−07 1.8133649E−07  2.2789366E−07 −4.7895393E−08 6  1.2025566E−01 −1.1095032E−01   4.0600006E−02 −2.5151177E−03 12  8.3745456E−09 3.9281284E−09 −4.8761656E−10 −5.8298476E−10 13 −2.3092798E−08 9.5595448E−09 −6.0074431E−09  8.2532367E−10

TABLE 11 EXAMPLE 11 (A) Si Ri Di Ndj νdj  1 21.2615 1.30000 1.7550 52.3  2 4.1145 2.28766  *3 −12.1823 1.04000 1.5339 55.9  *4 1.9557 1.10403  *5 2.9735 2.51285 1.6140 25.5  *6 12.3269 0.35517  7(St) ∞ 0.30000  8 6.5531 2.65028 1.7725 49.6  9 −3.0630 0.20000  10 −3.7335 0.64189 1.9229 18.9  11 ∞ 0.15000 *12 6.9865 2.06464 1.5339 55.9 *13 −2.1919 0.15000  14 ∞ 0.30000 1.5168 64.2  15 ∞ 1.00000 IMAGE ∞ PLANE (B) L 17.3 Bf 2.7 f 1.37 f1 −6.99 f2 −3.08 f3 5.79 f4 3.07 f5 −4.05 f6 3.39 f56 6.09 f123 −3.61 ER1 6.4 (C) SURFACE NUMBER KA RB3 RB4 RB5 RB6 3 0.0000000E+00 4.0030836E−02 −1.0978633E−03 −1.3300128E−03  −3.0086781E−04 4 0.0000000E+00 8.0798539E−02 −3.0802319E−02 2.2548922E−02  9.5633228E−03 5 0.0000000E+00 7.1068450E−04  2.0112218E−02 2.7754028E−03  1.9626136E−03 6 0.0000000E+00 −8.1581714E−04   2.0512080E−02 8.6494969E−03 −1.5514775E−02 12 0.0000000E+00 2.6103399E−03 −9.2012878E−03 3.7392207E−04  4.8367713E−04 13 0.0000000E+00 −3.9477637E−03   1.4980594E−02 −1.6230684E−03  −7.5187890E−04 SURFACE NUMBER RB7 RB8 RB9 RB10 RB11 3 −3.4687705E−05  2.4337603E−06  2.6755794E−06  9.5090679E−07  2.2532408E−07 4 1.9033332E−04 −1.2515710E−03  −7.3921310E−04 −2.9532922E−04 −8.4603696E−05 5 5.9315789E−04 −2.9667214E−04  −2.4822761E−04 −3.3089052E−05  4.5968424E−05 6 1.5481397E−02 2.0020281E−02 −2.6715115E−03 −2.0751377E−02 −1.6882436E−02 12 1.1963182E−05 1.7017932E−05  1.1736365E−06 −2.1690137E−07 −2.6186282E−07 13 1.2811034E−05 9.2428742E−05  3.4058412E−06  6.8066107E−06 −1.2187194E−06 SURFACE NUMBER RB12 RB13 RB14 RB15 RB16 3  3.1528366E−08 −4.2699340E−09 −4.0815331E−09 −1.5240774E−09 −3.3602663E−10 4 −1.0804934E−05  6.7624506E−06  6.6941674E−06  3.4468855E−06  1.1970826E−06 5  2.9920500E−05  7.3372810E−06 −2.2965307E−06 −3.4082319E−06 −1.8919129E−06 6  1.4804415E−02 −1.6264277E−02  8.4785004E−02 −7.3952464E−02 −3.4488381E−02 12 −1.9271418E−07 −1.4410273E−07 −6.2104490E−08 −1.2951020E−08  5.4340202E−09 13 −1.2422074E−06 −4.1657370E−07 −6.7358194E−09  8.6980017E−08  6.5710046E−08 SURFACE NUMBER RB17 RB18 RB19 RB20 3 −1.8407798E−11 3.5287787E−11  6.8781715E−12 −1.1934338E−12 4  1.5827714E−07 −1.2133728E−07  −9.4729269E−08  1.8096803E−08 5 −4.1038264E−07 1.8322269E−07  2.2993329E−07 −4.5088087E−08 6  1.2025955E−01 −1.1094771E−01   4.0586491E−02 −2.5431818E−03 12  8.2636905E−09 3.7839969E−09 −5.9342708E−10 −6.4837046E−10 13 −2.3091736E−09 9.5458611E−09 −6.0162942E−09  8.2092541E−10

TABLE 12 EXAMPLE 12 (A) Si Ri Di Ndj νdj  1 18.7463 1.1000 1.8348 42.7  2 4.5093 2.31246  *3 −16.0435 1.08823 1.5339 55.0  *4 1.8553 1.19022  *5 3.2054 2.70000 1.5236 30.3  *6 16.5379 0.43533  7(St) ∞ 0.30000  8 6.0100 2.65021 1.7550 52.3  9 −3.1037 0.20000  10 −3.6049 0.80002 1.9591 17.5  11 59.5256 0.15001 *12 5.4301 2.28264 1.5339 55.9 *13 −2.1206 0.15000  14 ∞ 0.30000 1.5168 64.2  15 ∞ 2.442192z IMAGE ∞ PLANE (B) L 18.0 Bf 2.8 f 1.32 f1 −7.37 f2 3.05 f3 6.34 f4 3.10 f5 −3.52 F6 3.19 f56 5.46 f123 −3.48 ER1 6.3 (C) SURFACE NUMBER KA RB3 RB4 RB5 RB6 3 0.0000000E+00  3.8588961E−02 −1.3494183E−03 −1.3540159E−03  −2.9776191E−04 4 0.0000000E+00  7.9672693E−02 −2.9876635E−02 2.3460175E−02  9.7136156E−03 5 0.0000000E+00 −9.6107661E−04  2.3118235E−02 2.1559144E−03  1.6361936E−03 6 0.0000000E+00 −2.5100752E−03  2.0696071E−02 8.4811231E−03 −2.0325189E−02 12 0.0000000E+00  2.1629233E−03 −7.7035054E−03 4.6995359E−04 −4.7153229E−04 13 0.0000000E+00 −3.3902156E−03  1.6107442E−02 −1.5065148E−03  −8.2248244E−04 SURFACE NUMBER RB7 RB8 RB9 RB10 RB11 3 −3.2707755E−05  3.0182900E−06 2.8107693E−06  9.7402655E−07  2.2692522E−07 4 1.7086551E−04 −1.2682795E−03  −7.4118481E−04  −2.9207151E−04 −8.1141431E−05 5 5.5584849E−04 −2.7084839E−04  −2.3119476E−04  −2.8541246E−05  4.5429694E−05 6 1.4264469E−02 2.2585431E−02 2.7609814E−04 −1.9806829E−02 −1.7799396E−02 12 1.0420325E−04 1.1414584E−05 2.9844857E−07  4.0619230E−08 −4.8492210E−09 13 −2.2799213E−05  8.3872169E−05 3.3004940E−05  6.7518797E−08 −1.0884750E−06 SURFACE NUMBER RB12 RB13 RB14 RB15 RB16 3  3.1182456E−08 −4.6398634E−09 −4.1777359E−09 −1.5293378E−09 −3.2668593E−10 4 −8.5567475E−06  7.9271014E−06  7.1906501E−06  3.6111790E−06  1.2231332E−06 5  2.8698186E−05  6.6645682E−06 −2.4498025E−06 −3.3215772E−06 −1.7597042E−06 6  1.2951281E−02 −1.8017420E−02  8.3943488E−02 −7.3842160E−02 −3.3860370E−02 12 −6.3716453E−08 −1.1691557E−07 −6.4592244E−08 −1.9209433E−08  1.5356114E−09 13 −1.2015341E−06 −4.1181210E−07 −1.0972676E−08  6.4795619E−08  6.4555678E−08 SURFACE NUMBER RB17 RB18 RB19 RB20 3 −1.3322138E−11 3.6834952E−11  6.6513899E−12 −1.2743815E−12 4  1.4260641E−07 −1.4222220E−07  −1.0855936E−07  9.8137275E−09 5 −3.1417589E−07 2.2848289E−07  2.3984785E−07 −5.8598406E−08 6  1.2159895E−01 −1.0984309E−01   4.0775212E−02 −3.7627941E−03 12  6.7249144E−09 3.4544257E−09 −4.7020559E−10 −3.9899904E−10 13 −2.3404754E−08 9.4834428E−09 −5.9758082E−09  8.5899942E−10

TABLE 13 EXAMPLE 13 (A) Si Ri Di Ndj νdj  1 17.7341 1.10000 1.8348 42.7  2 4.4617 2.31398  *3 −18.2169 1.05272 1.5339 55.9  *4 1.6925 1.19321  *5 3.0699 2.78256 1.5836 30.3  *6 18.1145 0.42953  7(St) ∞ 0.30865  8 5.9552 2.20510 1.7550 52.3  9 −3.0974 0.20000  10 −4.0786 0.50756 2.1435 17.8  11 20.5799 0.15000 *12 5.5532 2.32603 1.5339 55.9 *13 −1.9514 0.15000  14 ∞ 0.30000 1.5168 64.2  15 ∞ 2.385494z IMAGE ∞ PLANE (B) L 17.3 Bf 2.7 f 1.24 f1 −7.42 f2 −2.85 f3 5.93 f4 3.01 f5 −3.38 f6 3.03 f56 5.17 f123 −3.46 ER1 6.5 (C) SURFACE NUMBER KA RB3 RB4 RB5 RB6 3 0.0000000E+00  3.8487440E−02 −1.4596050E−03 −1.3650318E−03  −2.9500962E−04 4 0.0000000E+00  7.4574264E−02 −3.0193585E−02 2.3267204E−02  9.8160113E−03 5 0.0000000E+00 −3.0972246E−03  2.2730622E−02 2.2779063E−03  1.8071022E−03 6 0.0000000E+00 −2.6016501E−03  2.3051605E−02 9.6294347E−03 −2.1420725E−02 12 0.0000000E+00 −1.8727334E−03 −8.0348140E−03 5.9209228E−04  5.3715895E−04 13 0.0000000E+00 −4.3095631E−03  1.5612698E−02 −1.3967061E−03  −8.3499609E−04 SURFACE NUMBER RB7 RB8 RB9 RB10 RB11 3 −3.1224311E−05  3.4257304E−06  2.8925086E−06  9.8607153E−07  2.2763519E−07 4 1.6707089E−04 −1.2794907E−03  −7.4487643E−04 −2.9154202E−04 −7.9684984E−05 5 6.3193013E−04 −2.5556743E−04  −2.3586080E−04 −3.5015245E−05  4.1599093E−05 6 1.3517336E−02 2.2975346E−02  8.7147609E−04 −1.9398953E−02 −1.7730221E−02 12 1.2118341E−04 1.2949639E−05 −8.4618077E−07 −8.2764637E−07 −3.8654847E−07 13 −3.0578642E−05  8.2270656E−05  3.3359394E−05  7.2366377E−06 −8.0841479E−07 SURFACE NUMBER RB12 RB13 RB14 RB15 RB16 3  3.0836953E−08 −4.8445148E−09 −4.2159469E−09 −1.5304181E−09 −3.2360429E−10 4 −7.3962712E−06  8.6023891E−06  7.5137963E−06  3.7368498E−06  1.2588770E−06 5  2.7169597E−05  6.3417841E−06 −2.3381583E−06 −3.1386667E−06 −1.6234787E−06 6  1.2767967E−02 −1.8248460E−02  8.3796722E−02 −7.3872430E−02 −3.3730713E−02 12 −2.0423657E−07 −1.4085738E−07 −6.0178227E−08 −1.2395011E−08  5.5935639E−09 13 −1.0765061E−06 −3.6399092E−07  6.5674289E−09  8.9261729E−08  6.5624404E−08 SURFACE NUMBER RB17 RB18 RB19 RB20 3 −1.2089246E−11 3.7690265E−11  6.9324349E−12 −1.4351974E−12 4  1.4466297E−07 −1.4930268E−07  −1.1597888E−07  6.2952088E−09 5 −2.4162846E−07 2.5761970E−07  2.4022973E−07 −7.0017936E−08 6  1.2160877E−01 −1.0971800E−01   4.0723204E−02 −3.8030623E−03 12  8.3326196E−09 3.7828914E−09 −6.7326118E−10 −7.1814722E−10 13 −2.3472942E−08 9.2897340E−09 −6.1178469E−09  7.7694390E−10

TABLE 14 EXAMPLE 14 (A) Si Ri Di Ndj νdj  1 19.5408 1.10000 1.7725 49.6  2 4.6528 2.34575  *3 −12.1993 1.04005 1.5339 55.9  *4 2.2827 1.15665  *5 3.4648 2.32737 1.6336 23.6  *6 7.4016 0.58440  7(St) ∞ 0.50011  8 6.4935 2.48664 1.7550 52.3  9 −3.3707 0.20000  10 −4.2419 0.80001 1.9229 18.9  11 −30.3670 0.15000 *12 6.9227 2.41814 1.5339 55.9 *13 −2.3036 0.15000  14 ∞ 0.30000 1.5168 64.2  15 ∞ 2.39381 IMAGE ∞ PLANE (B) L 17.9 Bf 2.7 f 1.36 f1 −8.17 f2 −3.51 f3 8.36 f4 3.30 f5 −5.42 f6 3.56 f56 5.08 f123 −3.05 ER1 6.6 (C) SURFACE NUMBER KA RB3 RB4 RB5 RB6 3 0.0000000E+00 3.8301292E−02 −1.3020555E−03 −1.2466622E−03  −2.9505889E−04 4 0.0000000E+00 8.1476528E−02 −3.0265840E−02 2.3371804E−02  9.9953925E−03 5 0.0000000E+00 5.4458849E−03  2.2404489E−02 3.0300218E−03  1.8642040E−03 6 0.0000000E+00 5.3186943E−03  2.0389408E−02 8.3951141E−03 −1.6262039E−02 12 0.0000000E+00 7.2131851E−03 −6.9864812E−03 5.9346404E−04  4.9420028E−04 13 0.0000000E+00 1.3649383E−03  1.5911569E−02 −1.5122789E−03  −7.3084818E−04 SURFACE NUMBER RB7 RB8 RB9 RB10 RB11 3 −3.1002177E−05  3.7482005E−06  3.0486299E−06  1.0406199E−06  2.4297599E−07 4 3.7272084E−04 −1.1833138E−03  −7.1648427E−04 −2.8879131E−04 −8.3142149E−05 5 5.2000539E−04 −3.2335663E−04  −2.5236837E−04 −3.0495498E−05  4.8987603E−05 6 1.6576462E−02 2.1866804E−02 −1.5067169E−03 −2.1018727E−02 −1.8201761E−02 12 1.0756043E−04 1.0852771E−05 −1.0320116E−06 −8.9658128E−07 −4.3334361E−07 13 2.1585100E−05 9.5768040E−05  3.4894164E−05  6.6447647E−06 −1.3189784E−06 SURFACE NUMBER RB12 RB13 RB14 RB15 RB16 3  3.3371340E−08 −4.4381748E−09 −4.3125566E−09 −1.6231903E−09 −3.6930741E−10 4 −1.0694879E−05  6.6259263E−06  6.5606052E−06  3.3576507E−06  1.1447504E−06 5  3.1759224E−05  8.1309274E−06 −2.0822846E−06 −3.4210113E−06 −1.9528700E−06 6  1.3319810E−02 −1.7854956E−02  8.4430365E−02 −7.2822713E−02 −3.4045007E−02 12 −2.3156270E−07 −1.5786055E−07 −6.7029221E−08 −1.4871140E−08  4.8393780E−09 13 −1.3165378E−06 −4.5225576E−07 −2.0413830E−08  8.2839220E−08  6.5138606E−08 SURFACE NUMBER RB17 RB18 RB19 RB20 3 −2.3379546E−11 3.5696230E−11  7.0313334E−12 −1.0661587E−12 4  1.2971632E−07 −1.3457211E−07  −1.0077472E−07  1.5208511E−08 5 −4.4839697E−07 1.6565839E−07  2.2840819E−07 −3.8057320E−08 6  1.2154545E−01 −1.1009769E−01   4.0568157E−02 −3.6813858E−03 12  8.2033742E−09 3.8516774E−09 −5.2146977E−10 −5.6827939E−10 13 −2.4317763E−08 9.7452517E−09 −6.1738542E−09  8.7715077E−10

TABLE 15 EXAMPLE 15 (A) Si Ri Di Ndj νdj  1 20.8161 1.10000 1.7725 49.6  2 4.3148 2.37552  *3 −14.5157 1.04005 1.5339 55.9  *4 2.7852 0.67607  *5 3.4325 2.22028 1.6336 23.6  *6 4.4185 0.76934  7(St) ∞ 0.50011  8 6.1488 2.28866 1.7550 52.3  9 −3.5492 0.20000  10 −4.2337 0.80001 1.9229 18.9  11 −19.3225 0.15000 *12 7.3174 2.52643 1.5339 55.9 *13 −3.1296 0.15000  14 ∞ 0.30000 1.5168 64.2  15 ∞ 2.585642z IMAGE ∞ PLANE (B) L 17.6 Bf 2.9 f 1.32 f1 −7.26 f2 −4.29 f3 12.96 f4 3.31 f5 −6.03 f6 3.41 f56 4.35 f123 −2.41 ER1 6.5 (C) SURFACE NUMBER KA RB3 RB4 RB5 RB6 3 0.0000000E+00 3.7152072E−02 −1.2997268E−03 −1.3456267E−03  −2.9432181E−04 4 0.0000000E+00 8.2250176E−02 −3.0369752E−02 2.3357276E−02  9.9616608E−03 5 0.0000000E+00 1.0150619E−02  2.6860193E−02 4.1421179E−03  2.1411002E−03 6 0.0000000E+00 9.5198367E−04  2.6845516E−02 7.5302929E−03 −1.7009971E−02 12 0.0000000E+00 8.0590170E−03 −7.0079690E−03 5.9092907E−04  4.9343813E−04 13 0.0000000E+00 2.8488226E−03  1.6136936E−02 −1.5138456E−03  −7.5390828E−04 SURFACE NUMBER RB7 RB8 RB9 RB10 RB11 3 −3.0563181E−05  3.9170890E−06  3.0999162E−06  1.0540443E−06  2.4604648E−07 4 3.6073890E−04 −1.1909755E−03  −7.2059901E−04 −2.9075197E−04 −8.3978586E−05 5 5.6832605E−04 −3.2015090E−04  −2.5397174E−04 −3.2179445E−05  4.8965057E−05 6 1.7751133E−02 2.4282095E−02  4.5583807E−04 −2.0326982E−02 −1.8852099E−02 12 1.0656663E−04 1.0220513E−05 −1.2985890E−07 −9.4714948E−07 −4.5091585E−07 13 1.0742549E−05 9.2173174E−05  3.3444649E−05  6.2772145E−06 −1.3914252E−05 SURFACE NUMBER RB12 RB13 RB14 RB15 RB16 3  3.3973125E−08 −4.3383843E−09 −4.3101072E−09 −1.6290643E−09 −3.7154716E−10 4 −1.1006513E−05  6.5325716E−06  6.5464383E−06  3.3655990E−06  1.1537883E−06 5  3.1905703E−05  8.0212348E−06 −2.1933012E−06 −3.4304616E−06 −1.9840205E−06 6  1.2166831E−02 −1.8720139E−02  8.4163074E−02 −7.2535532E−02 −3.3415378E−02 12 −2.4874429E−07 −1.6276673E−07 −7.0797480E−08 −1.6468885E−08  4.2234036E−09 13 −1.3161231E−06 −4.4255484E−07 −2.0303969E−08  8.8116116E−08  6.5428728E−08 SURFACE NUMBER RB17 RB18 RB19 RB20 3 −2.4650897E−11 3.5362554E−11  6.9508352E−12 −1.0700161E−12 4  1.3697998E−07 −1.3193906E−07  −1.0015688E−07  1.4985326E−08 5 −4.4800962E−07 1.8313283E−07  2.2691604E−07 −3.8419262E−08 6  1.2222786E−01 −1.0963581E−01   4.0565197E−02 −4.3384751E−03 12  7.9592934E−09 4.2115961E−09 −5.2493470E−10 −5.3834510E−10 13 −2.5659319E−08 9.6844929E−09 −6.2089107E−09  9.4434420E−10

TABLE 16 EXAMPLE 16 (A) Si Ri Di Ndj νdj  1 18.7533 1.10000 1.7725 49.6  2 4.3303 2.57437  *3 −6.0784 1.10069 1.5339 55.9  *4 1.8968 1.00457  *5 2.8661 2.86877 1.6336 23.6  *6 18.5046 0.26287  7(St) ∞ 0.30020  8 5.4023 2.61305 1.6180 63.3  9 −2.8661 0.20000 *10 −11.1783 0.80000 1.6336 23.6 *11 3.6728 0.15000 *12 4.1487 2.37759 1.5339 55.9 *13 −2.2022 1.45000  14 ∞ 0.30000 1.5168 64.2  15 ∞ 0.59871 IMAGE ∞ PLANE (B) L 17.6 Bf 2.2 f 1.31 f1 −7.54 f2 −2.58 f3 5.00 f4 3.45 f5 −4.27 f6 3.10 f56 5.08 f123 −3.63 ER1 6.4 (C) SURFACE NUMBER KA RB3 RB4 RB5 RB6 3 0.0000000E+00  3.6657033E−02 −1.1693465E−03 −1.0696269E−03 −2.1402853E−04  4 0.0000000E+00  3.8072568E−02 −2.3112886E−03  1.7887996E−02 7.1533657E−03 5 0.0000000E+00 −1.1974054E−02  1.5962746E−02  2.4764019E−03 1.5499029E−03 6 0.0000000E+00 −2.4909692E−03  2.0610524E−02 −4.5992208E−03 −1.5270179E−02  10 1.0000000E+00 −8.0725986E−03 −1.1831671E−02  8.1539058E−04 2.0518478E−04 11 1.0000000E+00 −1.4837526E−02 −1.8995953E−03 −7.7828305E−04 1.4135008E−05 12 0.0000000E+00  8.2105919E−03 −7.9168456E−03  3.7999098E−04 3.1885879E−04 13 0.0000000E+00  8.9302603E−03  1.5224564E−02 −2.8235937E−03 −9.3350545E−04  SURFACE NUMBER RB7 RB8 RB9 RB10 RB11 3 −1.8362935E−05  3.7072483E−06  2.2919507E−06  7.3540686E−07  1.6082904E−07 4 −3.4055181E−04  −1.1962724E−03  −6.0106857E−04 −1.9787773E−04 −3.4109616E−05 5 4.6728857E−04 −3.1431346E−04  −2.6662330E−04 −5.6285323E−05  2.9468305E−05 6 1.7786778E−02 1.9760912E−02 −4.0411666E−03 −2.1885250E−02 −1.7431835E−02 10 −1.8443362E−04  −8.3541204E−05   2.4485575E−05  3.8479657E−05  9.7995834E−06 11 5.7851345E−05 1.4053162E−05 −2.1648860E−06 −2.1189145E−06 −9.2687142E−07 12 5.7961484E−05 4.7033433E−06  2.0526790E−07  2.1351975E−07  6.7858798E−09 13 3.3434863E−05 1.0792124E−04  3.7305926E−05  6.5004409E−06 −1.6080304E−06 SURFACE NUMBER RB12 RB13 RB14 RB15 RB16 3  1.7840356E−08 −5.7442838E−09 −3.7072607E−09 −1.2231102E−09 −2.0449764E−10  4  1.0485822E−05  1.3957976E−05  8.2525630E−08  3.2415168E−06 7.0349302E−07 5  2.2993164E−05  6.3077195E−08 −1.2538044E−06 −2.2344046E−06 −1.1657029E−06  6  1.4852625E−02 −1.6813019E−02  8.5484969E−02 −7.3322171E−02 −3.3300632E−02  10 −1.9091660E−05  0.0000000E+00  0.0000000E+00  0.0000000E+00 0.0000000E+00 11 −5.9359664E−07  0.0000000E+00  0.0000000E+00  0.0000000E+00 0.0000000E+00 12 −1.1509747E−07 −1.4222116E−07 −7.4269970E−08 −2.1355037E−08 1.8946094E−09 13 −1.4532413E−06 −5.3485351E−07 −5.6687041E−08  6.2037917E−08 5.9265913E−08 SURFACE NUMBER RB17 RB18 RB19 RB20 3 1.9397425E−11 4.0633566E−11 6.3533702E−12 −2.5429409E−12 4 −1.9467560E−07  −2.9079628E−07  −1.4021740E−07   4.1144932E−08 5 −7.9426355E−08  2.6701232E−07 2.1639629E−07 −8.3019456E−08 6 1.1977025E−01 −1.1097353E−01  4.0617885E−02 −2.8915634E−03 10 0.0000000E+00 0.0000000E+00 0.0000000E+00  0.0000000E+00 11 0.0000000E+00 0.0000000E+00 0.0000000E+00  0.0000000E+00 12 7.9489272E−09 3.7856274E−09 −4.2847331E−10  −4.6756867E−10 13 −2.3314872E−08  9.9576950E−08 −5.7677101E−09   1.0174086E−09

TABLE 17 EXAMPLE 17 (A) Si Ri Di Ndj νdj  1 17.0720 1.10000 1.7725 49.6  2 4.8454 2.76434  *3 −11.5218 1.10069 1.5339 55.9  *4 1.9329 1.39107  *5 3.5446 3.13824 1.6336 23.6  *6 9.0612 0.37228  7(St) ∞ 0.30020  8 5.9129 2.61003 1.6180 63.3  9 −3.0024 0.20000 *10 −14.9178 0.80000 1.6336 23.6 *11 3.4594 0.15000 *12 3.9457 2.66775 1.5339 55.9 *13 −2.2480 1.45000  14 ∞ 0.30000 1.5168 64.2  15 ∞ 0.98160 IMAGE ∞ PLANE (B) L 19.2 Bf 2.6 f 1.31 f1 −9.12 f2 −3.01 f3 7.53 f4 3.63 f5 −4.36 f6 3.16 f56 5.01 f123 −2.93 ER1 7.2 (C) SURFACE NUMBER KA RB3 RB4 RB5 RB6 3 0.0000000E+00  2.9435396E−02 −1.4177565E−03 −1.0271427E−03 −1.9574916E−04 4 0.0000000E+00  6.3237880E−02 −2.0998794E−02  1.3045598E−02  6.1306700E−03 5 0.0000000E+00  1.1524321E−03  1.2825813E−02  1.5024288E−03  1.1291876E−03 6 0.0000000E+00 −2.4666675E−03  2.8157943E−02 −1.3113929E−02 −4.9130077E−03 10 1.0000000E+00 −5.6487593E−03 −1.5449110E−02 −1.3697411E−05 −2.5443167E−05 11 1.0000000E+00 −1.4999331E−02 −8.6372961E−03 −2.1505026E−03 −6.1354508E−05 12 0.0000000E+00 −3.0707778E−03 −6.3073038E−03  7.3331087E−04  3.1518354E−04 13 0.0000000E+00 −5.6048503E−03  1.6289539E−02 −2.5669546E−03 −7.5138339E−04 SURFACE NUMBER RB7 RB8 RB9 RB10 RB11 3 −1.4033216E−05  4.3022442E−06 2.2548755E−06 6.7730233E−07  1.3681069E−07 4 −1.6516443E−04  −9.4895306E−04  −4.7216004E−04  −1.5123450E−04  −2.3243903E−05 5 4.4383361E−04 −2.5270545E−04  −2.2637358E−04  −4.0144890E−05   3.4685321E−05 6 2.1988229E−02 1.4488640E−02 −9.9426912E−03  −2.2992864E−02  −1.4135637E−02 10 −2.3666339E−04  −3.8604781E−05  9.1489687E−05 8.5241718E−05  2.5745442E−05 11 1.3235293E−04 5.7819817E−05 1.2395774E−05 6.3328409E−07 −1.1241963E−06 12 4.7399959E−05 5.3470188E−06 2.8448009E−06 1.8194423E−06  6.3883485E−07 13 1.0700628E−04 1.2647514E−04 4.0657515E−05 6.8548781E−06 −1.6399011E−06 SURFACE NUMBER RB12 RB13 RB14 RB15 RB16 3 1.0802148E−08 −7.3223196E−09 −3.9428358E−09 −1.2191358E−09 −1.8518535E−10 4 1.0008595E−05  1.1485179E−05  6.3733967E−06  2.2240061E−06  2.6515664E−07 5 2.4636511E−05  6.8697121E−06 −1.1088391E−06 −2.2864177E−06 −1.2852731E−06 6 1.9463620E−02 −1.3722125E−02  8.5745911E−02 −7.5522070E−02 −3.6359720E−02 10 −2.7635685E−05   0.0000000E+00  0.0000000E+00  0.0000000E+00  0.0000000E+00 11 −2.8380372E−07   0.0000000E+00  0.0000000E+00  0.0000000E+00  0.0000000E+00 12 5.5540427E−08 −1.2444350E−07 −8.8088469E−08 −3.3302139E−08 −4.0048431E−09 13 −1.4808007E−06  −5.4159082E−07 −5.6569060E−08  6.8961522E−08  5.9732630E−08 SURFACE NUMBER RB17 RB18 RB19 RB20 3 2.8000483E−11 4.3070595E−11 6.6725349E−12 −2.6882543E−12 4 −3.3488685E−07  −3.0627740E−07  −1.1644221E−07   6.9038745E−08 5 −1.8694037E−07  2.0480220E−07 2.0068691E−07 −6.5659299E−06 6 1.1760476E−01 −1.1114909E−01  4.2269099E−02 −2.0315415E−03 10 0.0000000E+00 0.0000000E+00 0.0000000E+00  0.0000000E+00 11 0.0000000E+00 0.0000000E+00 0.0000000E+00  0.0000000E+00 12 5.8736764E−09 3.3824856E−09 −3.0079628E−10  −2.6066932E−10 13 −2.3215205E−08  9.9068760E−09 −5.8443570E−09   9.5513453E−10

TABLE 18 EXAMPLE 18 (A) Si Ri Di Ndj νdj  1 16.7345 1.10000 1.7725 49.6  2 4.2717 2.79711  *3 −8.6275 1.20000 1.5339 55.9  *4 1.6168 1.01194  *5 2.8941 3.02110 1.6336 23.6  *6 8.6673 0.45000  7(St) ∞ 0.25438  *8 4.5948 1.80000 1.5339 55.9  *9 −1.3632 0.10000 *10 −2.2134 0.80000 1.6336 23.6 *11 −4.6480 0.15000 *12 −7.5843 1.00000 1.5339 55.9 *13 −2.6051 1.45000  14 ∞ 0.40000 1.5168 64.2  15 ∞ 0.68725 IMAGE ∞ PLANE (B) L 16.1 Bf 2.4 f 1.11 f1 −7.72 f2 −2.70 f3 5.70 f4 2.20 f5 −7.64 f6 6.95 f56 18.65 f123 −2.76 ER1 6.4 (C) SURFACE NUMBER KA RB3 RB4 RB5 RB6 3 0.0000000E+00 1.8376947E−02 −5.3428328E−03 −1.2951218E−04 5.4303259E−05 4 0.0000000E+00 6.3288508E−02 −3.5180789E−03  3.1506309E−03 3.3508174E−03 5 0.0000000E+00 1.2031761E−02  2.3100557E−02 −4.4110329E−04 −3.9341123E−04  6 0.0000000E+00 1.7829189E−03  3.5030459E−02 −3.2861003E−03 2.2264469E−02 8 0.0000000E+00 2.2292669E−02 −6.3564319E−02 −1.7358398E−01 6.2469083E−01 9 0.0000000E+00 −2.5941784E−02  −1.8497313E−03 −1.2206569E−02 −7.1460535E−03  10 0.0000000E+00 −3.2890441E−02  −1.2012659E−02 −1.8612274E−03 −1.1183007E−04  11 0.0000000E+00 5.7748657E−03  3.7577243E−03  6.8418485E−04 4.6024309E−04 12 0.0000000E+00 2.9554380E−02  7.2675889E−03  2.8443979E−03 9.6136878E−04 13 0.0000000E+00 −1.1636875E−03   2.2544163E−02  2.8070136E−04 1.0623997E−03 SURFACE NUMBER RB7 RB8 RB9 RB10 RB11 3 1.9362798E−05  3.2746129E−06  7.3335348E−08 −1.4950844E−07 −6.5777459E−08 4 −9.3459970E−06  −5.1442930E−04 −2.9027767E−04 −1.0935559E−04 −3.4816294E−05 5 7.7968170E−04  2.6642848E−04 −4.2288520E−05 −5.4084700E−05 −1.7581980E−05 6 1.0739897E−02 −8.2927429E−03 −1.5453281E−02 −1.2431203E−02 −3.6556586E−03 8 −4.5147260E−01  −5.0237910E−01 −5.8003338E−02  8.9024805E−01  7.5187230E−01 9 −2.5813114E−03  −3.5566675E−04  3.7499554E−04  4.1456903E−04  2.2492494E−04 10 1.3947648E−04  2.0598768E−04  2.5514981E−04  2.9365547E−04  2.0454647E−04 11 2.0952609E−04 −1.1056394E−05 −1.0796510E−04 −1.2110051E−04 −8.3290614E−05 12 4.5658891E−04  2.9047296E−04  1.8029225E−04  8.6739520E−05  2.1016321E−05 13 1.6177879E−03  1.1739172E−03  6.2364874E−04  2.6106422E−04  8.1092650E−05 SURFACE NUMBER RB12 RB13 RB14 RB15 RB16 3 −1.9330797E−08 −4.3529890E−09 −6.1956473E−10 5.2122703E−11  7.8178794E−11 4 −8.3752040E−06 −5.5351217E−07  1.0679538E−06 9.1396066E−07  5.7438868E−07 5 −7.2237806E−06 −2.3404937E−06 −4.7441180E−07 9.2872587E−08  1.4558401E−07 6  4.3202333E−03  1.3650868E−02  1.2172522E−02 3.7164124E−03 −8.5634604E−04 8 −6.2723893E−01 −1.0180173E+00 −4.4302801E−01 2.5085363E−01  5.8097485E−01 9  2.7850599E−05 −9.5410488E−05 −1.4354071E−04 −1.4056834E−04  −1.0834837E−04 10  2.0369480E−04  1.3584905E−04  1.5353959E−04 1.1381183E−04  7.2943274E−05 11 −5.5997622E−05 −3.4346710E−05 −1.9081621E−05 −9.1243452E−06  −3.0270434E−06 12 −1.4884274E−05 −2.9620522E−05 −3.0699187E−05 −2.6361746E−05  −1.7141614E−05 13  2.9541427E−06 −2.0313280E−05 −2.1025459E−05 −1.5202983E−05  −9.0765060E−06 SURFACE NUMBER RB17 RB18 RB19 RB20 3 3.5876045E−11 1.0788517E−11 6.0209036E−13 −1.0793226E−12  4 2.7289819E−07 9.1673325E−08 1.2242891E−09 −3.1392286E−08  5 1.0324208E−07 3.2921505E−08 5.0452888E−09 −1.0064348E−08  6 −3.8176081E−03  8.1764038E−04 −3.0834732E−02  2.0454964E−02 8 1.1257663E+00 4.6518291E−02 −1.9855272E+00  9.8726163E−01 9 −6.3307968E−05  −1.6620135E−05  2.4654548E−05 5.7877260E−05 10 3.5902660E−05 4.8588021E−06 −1.9212217E−05  −3.6137559E−05  11 4.5774146E−07 2.2562856E−06 3.0213537E−06 3.1741450E−06 12 −9.6434065E−06  −3.6614049E−06  5.3695225E−07 3.1369738E−06 13 −4.5266524E−06  −1.7911022E−06  −2.9437146E−07  3.8877527E−07

TABLE 19 EXAMPLE 19 (A) Si Ri Di Ndj νdj  1 17.0382 1.10000 1.7725 49.6  2 4.2973 2.76873  *3 −11.6712 1.05001 1.5339 55.9  *4 1.9906 1.12033  *5 2.9828 2.80000 1.6336 23.6  *6 8.0480 0.77559  7(St) ∞ 0.25000  *8 4.7068 1.80000 1.5339 55.9  *9 −1.4215 0.10000 *10 −2.0997 0.80000 1.6336 23.6 *11 −3.1414 0.15000 *12 −7.8968 1.00004 1.5339 55.9 *13 −2.4687 1.00000  14 ∞ 0.30000 1.5168 64.2  15 ∞ 0.83900 IMAGE ∞ PLANE (B) L 15.8 Bf 2.0 f 1.01 f1 −7.73 f2 −3.10 f3 6.16 f4 2.28 f5 −14.23 f6 6.32 f56 8.14 f123 −3.15 ER1 6.5 (C) SURFACE NUMBER KA RB3 RB4 RB5 RB6 3 0.0000000E+00 1.9961573E−02 −5.0111720E−03 −5.8322837E−05  7.4642634E−05 4 0.0000000E+00 6.7887635E−02  1.9893512E−03  4.2006484E−03  3.2539335E−03 5 0.0000000E+00 1.5229389E−02  2.2128462E−02 −1.0181562E−03 −5.8141933E−04 6 0.0000000E+00 −5.5117055E−03   3.8005330E−02  4.8554621E−03  1.2860603E−02 8 0.0000000E+00 1.8510215E−02 −5.8055830E−02 −1.6814230E−01  6.2598079E−01 9 0.0000000E+00 −1.6913785E−02  −3.0327260E−03 −9.8632036E−03 −5.4405072E−03 10 0.0000000E+00 −3.4233119E−02  −9.8010896E−03 −2.3751906E−03 −7.8360373E−04 11 0.0000000E+00 1.6906935E−03 −9.0903748E−04 −8.5557590E−04 −4.8860022E−04 12 0.0000000E+00 3.2700613E−02  7.6825152E−03 −1.1893391E−04 −6.2763145E−04 13 0.0000000E+00 −5.4576695E−03   2.1088672E−02  5.7268761E−04  5.1260756E−04 SURFACE NUMBER RB7 RB8 RB9 RB10 RB11 3  1.9655477E−05  2.8356119E−06 −1.1782620E−07 −1.9993872E−07  −7.4552448E−08  4 −1.9370143E−04 −6.2034487E−04 −3.2823429E−04 −1.2873637E−04  −4.1972853E−05  5  7.1158064E−04  2.3785356E−04 −5.3839229E−05 −5.7862069E−05  −1.8318226E−05  6 −5.7733341E−03 −1.6980945E−02 −1.1836823E−02 5.9632792E−04 1.0366148E−02 8 −4.5485804E−01 −5.0734771E−01 −6.1249600E−02 8.9049669E−01 7.5553144E−01 9 −2.0277596E−03 −4.8654933E−04  1.7265868E−05 8.8221477E−05 2.4044007E−05 10 −1.6997512E−04  1.5365198E−04  2.9576208E−04 3.2822209E−04 1.9754673E−04 11 −4.8538283E−04 −4.6590266E−04 −3.6557741E−04 −2.4610370E−04  −1.3219641E−04  12 −7.4705995E−05  1.8663113E−04  1.9033868E−04 1.0371759E−04 2.3123497E−05 13  1.0102027E−03  8.1073703E−04  4.7358111E−04 2.2950613E−04 9.8143599E−05 SURFACE NUMBER RB12 RB13 RB14 RB15 RB16 3 −1.9694511E−08 −3.6468998E−09 −2.4119429E−10  1.8624409E−10 1.1702561E−10 4 −1.0710644E−05 −1.1343050E−06  1.0497823E−06  1.0260864E−06 6.7674887E−07 5 −7.1710730E−06 −2.2604713E−08 −5.0718617E−07 −3.1527729E−10 5.2851463E−08 6  1.6888488E−02  1.4171716E−02  6.8529281E−03 −8.2778354E−03 −7.6941262E−03  8 −6.2002192E−01 −1.0107167E+00 −4.3689249E−01  2.5453041E−01 5.8073119E−01 9 −4.6330350E−05 −7.9717312E−05 −8.0910814E−05 −6.5796550E−05 −4.4201187E−05  10  1.5722144E−04  1.1714162E−04  8.1325883E−05  5.2040890E−05 2.9896650E−05 11 −6.7256871E−05 −3.0268037E−05 −1.0966304E−05 −1.8275622E−06 1.9295311E−08 12 −2.3882887E−05 −4.2469348E−05 −4.2540766E−05 −3.3758637E−05 −2.2449432E−05  13  3.1563395E−05  4.6134411E−06 −3.8220422E−06 −5.1235574E−06 −4.1632632E−06  SURFACE NUMBER RB17 RB18 RB19 RB20 3 4.2855210E−11 1.0914310E−11 −3.5927702E−13 −1.4502877E−12  4 3.3639967E−07 1.2076485E−07  9.1904417E−09 −3.3768696E−08  5 3.5597801E−08 5.7024869E−10  1.4531935E−09 8.5940370E−10 6 −9.7885717E−03  −8.5486134E−03  −3.2992581E−02 3.7802525E−02 8 1.1210284E+00 3.7692815E−02 −1.9967236E+00 9.7717975E−01 9 −2.1598845E−05  −1.1183304E−06   1.5557615E−05 2.7873572E−05 10 1.3875711E−05 2.5656254E−06 −5.1051905E−06 −9.9159985E−06  11 3.0615996E−06 3.0372872E−06  2.5983210E−06 2.0710373E−06 12 −1.2055512E−05  −3.9743613E−06   1.5604414E−06 4.8901425E−06 13 −2.8619462E−06  −1.9201815E−06  −1.2626805E−06 −8.5529088E−07 

TABLE 20 CONDITIONAL FORMULA (1) (4) (7) (13) (14) (15) EXAM- (D6 + (2) (3) (R8 + R9/ (5) (6) (R12 + R13)/ (8) (9) (10) (11) (12) νd3 + (R3 + R4)/ (R5 + R6)/ PLE D7)/f D12/f f56/f (R8 − R9) R2/f D3/f (R12 − R13) f5/f D2/f D5/f L/f Bf/f νd5 (R3 − R4) (R5 − R6) 1 0.47 1.92 3.92 0.35 3.10 0.75 0.42 −3.39 1.75 1.96 13.18 1.99 42.51 0.68 −1.90 2 0.45 1.58 4.21 0.35 3.25 0.77 0.44 −3.30 1.69 2.00 13.01 2.03 42.51 0.72 −1.92 3 0.52 2.01 3.56 0.36 3.34 0.77 0.48 −3.77 1.75 2.00 13.48 1.98 42.51 0.69 −2.13 4 0.52 2.06 3.59 0.38 3.24 0.77 0.45 −3.73 1.71 2.01 13.52 1.99 42.51 0.77 −2.27 5 0.50 1.94 3.99 0.34 3.23 0.79 0.41 −3.56 1.79 2.04 13.71 2.07 42.51 0.77 −2.10 6 0.46 1.80 3.98 0.35 3.14 0.76 0.42 −3.44 1.70 1.96 13.11 1.99 42.51 0.71 −2.07 7 0.47 1.94 3.84 0.35 3.15 0.77 0.42 −3.44 1.78 1.96 13.39 2.01 44.42 0.72 −1.81 8 0.47 1.94 3.81 0.34 3.18 0.77 0.40 −3.34 1.77 1.98 13.40 2.04 44.42 0.71 −1.74 9 0.50 1.62 4.34 0.37 3.27 0.77 0.46 −3.00 1.70 2.01 13.19 2.09 49.17 0.73 −1.70 10 0.49 1.61 4.20 0.37 3.11 0.77 0.45 −2.98 1.69 1.89 12.91 2.02 44.42 0.73 −1.78 11 0.48 1.51 4.46 0.36 3.01 0.76 0.52 −2.96 1.67 1.84 12.69 2.00 44.42 0.72 −1.64 12 0.56 1.73 4.14 0.32 3.42 0.82 0.44 −2.67 1.75 2.05 13.64 2.11 47.74 0.79 −1.48 13 0.60 1.88 4.17 0.32 3.60 0.85 0.48 −2.73 1.87 2.24 13.95 2.20 43.07 0.83 −1.41 14 0.80 1.78 3.75 0.32 3.43 0.77 0.50 −4.00 1.73 1.72 13.17 2.02 42.51 0.68 −2.76 15 0.96 1.92 3.30 0.27 3.28 0.79 0.55 −4.58 1.80 1.69 13.33 2.23 42.51 0.68 −7.96 16 0.43 1.82 3.89 0.31 3.32 0.84 0.31 −3.27 1.97 2.20 13.49 1.72 47.22 0.52 −1.37 17 0.52 2.04 3.23 0.33 3.71 0.84 0.27 −3.34 2.12 2.40 14.72 2.01 47.22 0.71 −2.29 18 0.63 0.90 16.79 0.54 3.85 1.08 2.05 −6.86 2.52 2.72 14.48 2.16 47.22 0.65 −2.00 19 1.01 0.99 8.04 0.54 4.25 1.04 1.91 −14.05 2.74 2.77 15.56 2.01 47.22 0.71 −2.18

TABLE 21 (16) EXAM- (R1 + R2)/ (17) (18) (19) (20) (21) PLE (R1 − R2) f123/f f3/f D9/f f4/f ER1/f 1 1.61 −2.27 5.00 0.14 2.36 4.66 2 1.60 −2.36 4.94 0.15 2.34 4.75 3 1.61 −2.26 5.43 0.15 2.45 4.68 4 1.55 −2.22 5.20 0.15 2.44 4.69 5 1.61 −2.17 5.33 0.15 2.44 4.94 6 1.58 −2.21 5.13 0.15 2.33 4.62 7 1.58 −2.35 5.03 0.15 2.44 4.67 8 1.61 −2.36 5.01 0.15 2.47 4.72 9 1.65 −2.49 4.74 0.15 2.32 4.69 10 1.55 −2.48 4.66 0.15 2.27 4.70 11 1.48 −2.64 4.23 0.15 2.25 4.71 12 1.63 −2.64 4.81 0.15 2.35 4.80 13 1.67 −2.79 4.78 0.16 2.43 5.22 14 1.63 −2.25 6.17 0.15 2.43 4.84 15 1.52 −1.83 9.84 0.15 2.52 4.93 16 1.60 −2.78 3.83 0.15 2.64 4.91 17 1.79 −2.25 5.77 0.15 2.78 5.49 18 1.59 −2.49 5.13 0.09 1.98 5.72 19 1.67 −3.11 6.09 0.10 2.25 6.43

With respect to the imaging lenses of Examples 1 through 19, in the imaging lenses of Examples 1 through 15, first lens L1, fourth lens L4 and fifth lens L5 are glass spherical lenses, and second lens L2, third lens L3 and sixth lens L6 are plastic aspheric lenses. In the imaging lenses of Examples 16 and 17, first lens L1 and fourth lens L4 are glass spherical lenses, and second lens L2, third lens L3, fifth lens L5 and sixth lens L6 are plastic aspheric lenses. In the imaging lenses of Examples 18 and 19, first lens L1 is a glass spherical lens, and second lens L2, third lens L3, fourth lens L4, fifth lens L5 and sixth lens L6 are plastic aspheric lenses.

Aberration diagrams of the imaging lenses according to Examples 1 through 19 are illustrated in FIG. 22, Sections A through D, FIG. 23, Sections A through D, FIG. 24, Sections A through D, FIG. 25, Sections A through D, FIG. 26, Sections A through D, FIG. 27, Sections A through D, FIG. 28, Sections A through D, FIG. 29, Sections A through D, FIG. 30, Sections A through D, FIG. 31, Sections A through D, FIG. 32, Sections A through D, FIG. 33, Sections A through D, FIG. 34, Sections A through D, FIG. 35, Sections A through D, FIG. 36, Sections A through D, FIG. 37, Sections A through D, FIG. 38, Sections A through D, FIG. 39, Sections A through D, and FIG. 40, Sections A through D, respectively.

Here, the aberration diagrams of Example 1 will be explained as an example, but the aberration diagrams of the other examples are similar to those of Example 1. FIG. 22, Section A, FIG. 22, Section B, FIG. 22, Section C and FIG. 22, Section D illustrate a spherical aberration, astigmatism, distortion (distortion aberration), and a lateral chromatic aberration (a chromatic aberration of magnification) in the imaging lens of Example 1, respectively. In the diagram of a spherical aberration, F represents F-number, and in the other diagrams, ω represents a half angle of view. In the diagram of distortion, a shift amount from an ideal image height 2f×tan(φ/2) is illustrated by using focal length f of the entire system and angle q of view (variable, 0≦φ≦ω). Each aberration diagram illustrates an aberration when d-line (587.56 nm) is a reference wavelength. The diagram of spherical aberrations illustrates aberrations also for F-line (wavelength 486.13 nm), C-line (wavelength 656.27 nm) and an offense against the sine condition (indicated as SNC). Further, the diagram of lateral chromatic aberrations illustrates aberrations for F-line and C-line. Since the kinds of line used in the diagram of lateral chromatic aberrations are the same as those used in the diagram of spherical aberrations, the descriptions are omitted in the diagram of lateral chromatic aberrations.

As these data show, the imaging lens of Examples 1 through 19 consists of six lenses, which are a small number of lenses, and producible in small size and at low cost. Further, it is possible to achieve an extremely wide angle of view of a full angle of view of about 187 to 213 degrees. Further, F-number is 2.0, which is small. Further, the imaging lens has excellent optical performance in which each aberration has been corrected in an excellent manner. These imaging lenses are appropriate for use in a surveillance camera, an in-vehicle camera for imaging an image on the front side, the lateral sides, the rear side or the like of a car, or the like.

[Embodiment of Imaging Apparatus]

FIG. 41 illustrates, as an example of usage, a manner of mounting an imaging apparatus including an imaging lens according to an embodiment of the present invention in a car 100. In FIG. 41, the car 100 includes an exterior camera 101 for imaging a driver's blind spot on a side of a seat next to the driver, an exterior camera 102 for imaging a driver's blind spot on a rear side of the car 100, and an interior camera 103 for imaging the same range as the driver's visual field. The interior camera 103 is attached to the back side of a rearview mirror. The exterior camera 101, the exterior camera 102, and the interior camera 103 are imaging apparatuses according to an embodiment of the present invention, and they include an imaging lens according to an example of the present invention and an imaging device for converting an optical image formed by the imaging lens into electrical signals.

The imaging lenses according to the examples of the present invention have the aforementioned advantages. Therefore, the exterior cameras 101 and 102, and the interior camera 103 can be structured also in small size and at low cost, and have wide angles of view. Further, they can obtain excellent images even in a peripheral portion of an image formation area.

So far, the present invention has been described by using embodiments and examples. However, the present invention is not limited to the aforementioned embodiments nor examples, and various modifications are possible. For example, the values of a curvature radius, a distance between surfaces, a refractive index, and an Abbe number of each lens element are not limited to the values in the aforementioned examples of numerical values, but may be other values.

In the aforementioned examples, all of the lenses consist of homogeneous materials. Alternatively, a gradient index lens having a distribution of refractive index may be used. Further, in some of the aforementioned examples, second lens L2 through sixth lens L6 consist of refraction-type lenses on which aspherical surfaces are formed. A diffraction optical element or elements may be formed on a surface or plural surfaces.

In the embodiment of the imaging apparatus, a case in which the present invention is applied to an in-vehicle camera was described with reference to the drawing. However, the use of the present invention is not limited to this purpose. For example, the present invention may be applied to a camera for a mobile terminal, a surveillance camera, and the like. 

What is claimed is:
 1. An imaging lens substantially consisting of six lenses of a negative first lens, a negative second lens, a positive third lens, a positive fourth lens, a negative fifth lens and a positive sixth lens in this order from an object side, wherein an object-side surface of the second lens has a shape having negative refractive power at a center, and including a part having positive refractive power in an area between the center and an effective diameter edge, and having negative refractive power at the effective diameter edge, and the refractive power at the effective diameter edge being weaker than the refractive power at the center, and wherein an object-side surface of the third lens is convex toward the object side, and wherein the following conditional formulas (17-4), (14-3) and (20) are satisfied: −3.5<f123/f<−1.0  (17-4); 0.5≦(R3+R4)/(R3−R4)≦0.80  (14-3); and 1.0<f4/f<4.0  (20), where f123: a combined focal length of the first lens, the second lens and the third lens, f: a focal length of an entire system, R3: a curvature radius of an object-side surface of the second lens, R4: a curvature radius of an image-side surface of the second lens, and f4: a focal length of the fourth lens.
 2. The imaging lens, as defined in claim 1, wherein the following conditional formula (11) is satisfied: 9<L/f<16  (11), where L: a length from an object-side surface of the first lens to an image plane on an optical axis when a back focus portion is a distance in air, and f: a focal length of an entire system.
 3. The imaging lens, as defined in claim 2, wherein the following conditional formula (11-3) is satisfied: 12.5<L/f<15.0  (11-3), where L: a length from an object-side surface of the first lens to an image plane on an optical axis when a back focus portion is a distance in air, and f: a focal length of an entire system.
 4. The imaging lens, as defined in claim 1, wherein the following conditional formula (12) is satisfied: 1<Bf/f<3  (12), where Bf: a length from an image-side surface of a most image-side lens to an image plane on an optical axis when the length is a distance in air, and f: a focal length of an entire system.
 5. The imaging lens, as defined in claim 4, wherein the following conditional formula (12-2) is satisfied: 1.7<Bf/f<2.3  (12-2), where Bf: a length from an image-side surface of a most image-side lens to an image plane on an optical axis when the length is a distance in air, and f: a focal length of an entire system.
 6. The imaging lens, as defined in claim 1, wherein the following conditional formula (13) is satisfied: vd3+vd5<50.0  (13), where vd3: an Abbe number of the material of the third lens for d-line, and vd5: an Abbe number of the material of the fifth lens for d-line.
 7. The imaging lens, as defined in claim 6, wherein the following conditional formula (13-2) is satisfied: 38.0<vd3+vd5<48.0  (13-2), where vd3: an Abbe number of the material of the third lens for d-line, and vd5: an Abbe number of the material of the fifth lens for d-line.
 8. The imaging lens, as defined in claim 1, wherein the following conditional formula (15) is satisfied: −10≦(R5+R6)/(R5−R6)≦−1  (15), where R5: a curvature radius of an object-side surface of the third lens, and R6: a curvature radius of an image-side surface of the third lens.
 9. The imaging lens, as defined in claim 8, wherein the following conditional formula (15-3) is satisfied: −3.5≦(R5+R6)/(R5−R6)≦−1.3  (15-3), where R5: a curvature radius of an object-side surface of the third lens, and R6: a curvature radius of an image-side surface of the third lens.
 10. The imaging lens, as defined in claim 1, wherein the following conditional formula (16) is satisfied: 1.1≦(R1+R2)/(R1−R2)≦3.0  (16), where R1: a curvature radius of an object-side surface of the first lens, and R2: a curvature radius of an image-side surface of the first lens.
 11. The imaging lens, as defined in claim 10, wherein the following conditional formula (16-2) is satisfied: 1.3≦(R1+R2)/(R1−R2)≦2.0  (16-2), where R1: a curvature radius of an object-side surface of the first lens, and R2: a curvature radius of an image-side surface of the first lens.
 12. The imaging lens, as defined in claim 1, wherein the following conditional formula (17-3) is satisfied: −3.2<f123/f<−1.8  (17-3), where f123: a combined focal length of the first lens, the second lens and the third lens, and f: a focal length of an entire system.
 13. The imaging lens, as defined in claim 1, wherein the following conditional formula (18) is satisfied: 2<f3/f<12  (18), where f3: a focal length of the third lens, and f: a focal length of an entire system.
 14. The imaging lens, as defined in claim 13, wherein the following conditional formula (18-3) is satisfied: 3.5<f3/f<10  (18-3), where f3: a focal length of the third lens, and f: a focal length of an entire system.
 15. The imaging lens, as defined in claim 1, wherein the following conditional formula (19) is satisfied: 0.01<D9/f<0.5  (19), where D9: an air space between the fourth lens and the fifth lens on an optical axis, and f: a focal length of an entire system.
 16. The imaging lens, as defined in claim 15, wherein the following conditional formula (19-1) is satisfied: 0.05<D9/f<0.3  (19-1), where D9: an air space between the fourth lens and the fifth lens on an optical axis, and f: a focal length of an entire system.
 17. The imaging lens, as defined in claim 1, wherein the following conditional formula (20-1) is satisfied: 1.5<f4/f<3.0  (20-1), where f4: a focal length of the fourth lens, and f: a focal length of an entire system.
 18. The imaging lens, as defined in claim 1, wherein the following conditional formula (21) is satisfied: 2.5<ER1/f<7.5  (21), where ER1: an effective radius of an object-side surface of the first lens, and f: a focal length of an entire system.
 19. The imaging lens, as defined in claim 18, wherein the following conditional formula (21-1) is satisfied: 2.5<ER1/f<8  (21-1), where ER1: an effective radius of an object-side surface of the first lens, and f: a focal length of an entire system.
 20. The imaging lens, as defined in claim 18, wherein the following conditional formula (21-4) is satisfied: 4.0<ER1/f<6.5  (21-4), where ER1: an effective radius of an object-side surface of the first lens, and f: a focal length of an entire system.
 21. The imaging lens, as defined in claim 1, wherein a stop is arranged between the third lens and the fourth lens.
 22. An imaging apparatus comprising: the imaging lens, as defined in claim 1, mounted thereon. 